pkg/front_end/testcases/nnbd/issue41437a.dart.weak.transformed.expect

library /*isNonNullableByDefault*/;
//
// Problems in library:
//
// pkg/front_end/testcases/nnbd/issue41437a.dart:18:25: Error: A value of type 'Future<dynamic>' can't be returned from a function with return type 'Future<bool>'.
//  - 'Future' is from 'dart:async'.
// Future<bool> test5() => getFutureNull(); // error
//                         ^
//
// pkg/front_end/testcases/nnbd/issue41437a.dart:27:27: Error: A value of type 'Future<dynamic>' can't be returned from a function with return type 'Future<bool>'.
//  - 'Future' is from 'dart:async'.
//   Future<bool> test5() => getFutureNull(); // error
//                           ^
//
// pkg/front_end/testcases/nnbd/issue41437a.dart:31:52: Error: A value of type 'Future<dynamic>' can't be assigned to a variable of type 'Future<bool>'.
//  - 'Future' is from 'dart:async'.
//   Future<bool> var1 = (() async => await getNull())(); // error
//                                                    ^
//
// pkg/front_end/testcases/nnbd/issue41437a.dart:34:58: Error: A value of type 'Future<dynamic>' can't be assigned to a variable of type 'Future<bool>'.
//  - 'Future' is from 'dart:async'.
//   Future<bool> var4 = (() async => await getFutureNull())(); // error
//                                                          ^
//
// pkg/front_end/testcases/nnbd/issue41437a.dart:35:46: Error: A value of type 'Future<dynamic>' can't be assigned to a variable of type 'Future<bool>'.
//  - 'Future' is from 'dart:async'.
//   Future<bool> var5 = (() => getFutureNull())(); // error
//                                              ^
//
import self as self;
import "dart:async" as asy;
import "dart:core" as core;
import "dart:_internal" as _in;

static method getNull() → dynamic
  return null;
static method getFutureNull() → asy::Future<dynamic> /* originally async */ {
  final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
  core::bool* :is_sync = false;
  FutureOr<dynamic>? :return_value;
  (dynamic) → dynamic :async_op_then;
  (core::Object, core::StackTrace) → dynamic :async_op_error;
  core::int :await_jump_var = 0;
  dynamic :await_ctx_var;
  dynamic :saved_try_context_var0;
  FutureOr<dynamic>:async_temporary_0;
  function :async_op([dynamic :result, dynamic :exception, dynamic :stack_trace]) → dynamic yielding 
    try {
      #L1:
      {
        final Null #t1 = null;
        if(#t1 is asy::Future<dynamic>) {
          [yield] let dynamic #t2 = asy::_awaitHelper(#t1, :async_op_then, :async_op_error, :async_op) in null;
          :async_temporary_0 = _in::unsafeCast<Null>(:result);
        }
        else {
          :async_temporary_0 = #t1;
        }
        :return_value = :async_temporary_0;
        break #L1;
      }
      asy::_completeOnAsyncReturn(:async_future, :return_value, :is_sync);
      return;
    }
    on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
      asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
    }
  :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
  :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
  :async_op.call();
  :is_sync = true;
  return :async_future;
}
static method getFutureBool() → asy::Future<core::bool> /* originally async */ {
  final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
  core::bool* :is_sync = false;
  FutureOr<core::bool>? :return_value;
  (dynamic) → dynamic :async_op_then;
  (core::Object, core::StackTrace) → dynamic :async_op_error;
  core::int :await_jump_var = 0;
  dynamic :await_ctx_var;
  dynamic :saved_try_context_var0;
  FutureOr<core::bool>:async_temporary_0;
  function :async_op([dynamic :result, dynamic :exception, dynamic :stack_trace]) → dynamic yielding 
    try {
      #L2:
      {
        final core::bool #t3 = true;
        if(#t3 is asy::Future<core::bool>) {
          [yield] let dynamic #t4 = asy::_awaitHelper(#t3, :async_op_then, :async_op_error, :async_op) in null;
          :async_temporary_0 = _in::unsafeCast<core::bool>(:result);
        }
        else {
          :async_temporary_0 = #t3;
        }
        :return_value = :async_temporary_0;
        break #L2;
      }
      asy::_completeOnAsyncReturn(:async_future, :return_value, :is_sync);
      return;
    }
    on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
      asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
    }
  :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
  :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
  :async_op.call();
  :is_sync = true;
  return :async_future;
}
static method test1() → asy::Future<core::bool> /* originally async */ {
  final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
  core::bool* :is_sync = false;
  FutureOr<core::bool>? :return_value;
  (dynamic) → dynamic :async_op_then;
  (core::Object, core::StackTrace) → dynamic :async_op_error;
  core::int :await_jump_var = 0;
  dynamic :await_ctx_var;
  dynamic :saved_try_context_var0;
  FutureOr<core::bool>:async_temporary_0;
  function :async_op([dynamic :result, dynamic :exception, dynamic :stack_trace]) → dynamic yielding 
    try {
      #L3:
      {
        [yield] let dynamic #t5 = asy::_awaitHelper(self::getNull(), :async_op_then, :async_op_error, :async_op) in null;
        final FutureOr<core::bool>#t6 = :result as{TypeError,ForDynamic,ForNonNullableByDefault} FutureOr<core::bool>;
        if(#t6 is asy::Future<core::bool>) {
          [yield] let dynamic #t7 = asy::_awaitHelper(#t6, :async_op_then, :async_op_error, :async_op) in null;
          :async_temporary_0 = _in::unsafeCast<core::bool>(:result);
        }
        else {
          :async_temporary_0 = #t6;
        }
        :return_value = :async_temporary_0;
        break #L3;
      }
      asy::_completeOnAsyncReturn(:async_future, :return_value, :is_sync);
      return;
    }
    on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
      asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
    }
  :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
  :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
  :async_op.call();
  :is_sync = true;
  return :async_future;
}
static method test2() → asy::Future<core::bool>
  return self::getNull() as{TypeError,ForDynamic,ForNonNullableByDefault} asy::Future<core::bool>;
static method test3() → core::bool
  return self::getNull() as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool;
static method test4() → asy::Future<core::bool> /* originally async */ {
  final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
  core::bool* :is_sync = false;
  FutureOr<core::bool>? :return_value;
  (dynamic) → dynamic :async_op_then;
  (core::Object, core::StackTrace) → dynamic :async_op_error;
  core::int :await_jump_var = 0;
  dynamic :await_ctx_var;
  dynamic :saved_try_context_var0;
  FutureOr<core::bool>:async_temporary_0;
  function :async_op([dynamic :result, dynamic :exception, dynamic :stack_trace]) → dynamic yielding 
    try {
      #L4:
      {
        [yield] let dynamic #t8 = asy::_awaitHelper(self::getFutureNull(), :async_op_then, :async_op_error, :async_op) in null;
        final FutureOr<core::bool>#t9 = :result as{TypeError,ForDynamic,ForNonNullableByDefault} FutureOr<core::bool>;
        if(#t9 is asy::Future<core::bool>) {
          [yield] let dynamic #t10 = asy::_awaitHelper(#t9, :async_op_then, :async_op_error, :async_op) in null;
          :async_temporary_0 = _in::unsafeCast<core::bool>(:result);
        }
        else {
          :async_temporary_0 = #t9;
        }
        :return_value = :async_temporary_0;
        break #L4;
      }
      asy::_completeOnAsyncReturn(:async_future, :return_value, :is_sync);
      return;
    }
    on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
      asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
    }
  :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
  :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
  :async_op.call();
  :is_sync = true;
  return :async_future;
}
static method test5() → asy::Future<core::bool>
  return let final<BottomType> #t11 = invalid-expression "pkg/front_end/testcases/nnbd/issue41437a.dart:18:25: Error: A value of type 'Future<dynamic>' can't be returned from a function with return type 'Future<bool>'.
 - 'Future' is from 'dart:async'.
Future<bool> test5() => getFutureNull(); // error
                        ^" in self::getFutureNull() as{TypeError,ForNonNullableByDefault} asy::Future<core::bool>;
static method test6() → asy::Future<core::bool>
  return self::getFutureBool();
static method test7() → asy::Future<core::bool> /* originally async */ {
  final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
  core::bool* :is_sync = false;
  FutureOr<core::bool>? :return_value;
  (dynamic) → dynamic :async_op_then;
  (core::Object, core::StackTrace) → dynamic :async_op_error;
  core::int :await_jump_var = 0;
  dynamic :await_ctx_var;
  dynamic :saved_try_context_var0;
  FutureOr<core::bool>:async_temporary_0;
  function :async_op([dynamic :result, dynamic :exception, dynamic :stack_trace]) → dynamic yielding 
    try {
      #L5:
      {
        final asy::Future<core::bool> #t12 = self::getFutureBool();
        if(#t12 is asy::Future<core::bool>) {
          [yield] let dynamic #t13 = asy::_awaitHelper(#t12, :async_op_then, :async_op_error, :async_op) in null;
          :async_temporary_0 = _in::unsafeCast<core::bool>(:result);
        }
        else {
          :async_temporary_0 = #t12;
        }
        :return_value = :async_temporary_0;
        break #L5;
      }
      asy::_completeOnAsyncReturn(:async_future, :return_value, :is_sync);
      return;
    }
    on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
      asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
    }
  :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
  :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
  :async_op.call();
  :is_sync = true;
  return :async_future;
}
static method test() → dynamic /* originally async */ {
  final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
  core::bool* :is_sync = false;
  FutureOr<dynamic>? :return_value;
  (dynamic) → dynamic :async_op_then;
  (core::Object, core::StackTrace) → dynamic :async_op_error;
  core::int :await_jump_var = 0;
  dynamic :await_ctx_var;
  function :async_op([dynamic :result, dynamic :exception, dynamic :stack_trace]) → dynamic yielding 
    try {
      #L6:
      {
        function test1() → asy::Future<core::bool> /* originally async */ {
          final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
          core::bool* :is_sync = false;
          FutureOr<core::bool>? :return_value;
          (dynamic) → dynamic :async_op_then;
          (core::Object, core::StackTrace) → dynamic :async_op_error;
          core::int :await_jump_var = 0;
          dynamic :await_ctx_var;
          dynamic :saved_try_context_var0;
          FutureOr<core::bool>:async_temporary_0;
          function :async_op([dynamic :result, dynamic :exception, dynamic :stack_trace]) → dynamic yielding 
            try {
              #L7:
              {
                [yield] let dynamic #t14 = asy::_awaitHelper(self::getNull(), :async_op_then, :async_op_error, :async_op) in null;
                final FutureOr<core::bool>#t15 = :result as{TypeError,ForDynamic,ForNonNullableByDefault} FutureOr<core::bool>;
                if(#t15 is asy::Future<core::bool>) {
                  [yield] let dynamic #t16 = asy::_awaitHelper(#t15, :async_op_then, :async_op_error, :async_op) in null;
                  :async_temporary_0 = _in::unsafeCast<core::bool>(:result);
                }
                else {
                  :async_temporary_0 = #t15;
                }
                :return_value = :async_temporary_0;
                break #L7;
              }
              asy::_completeOnAsyncReturn(:async_future, :return_value, :is_sync);
              return;
            }
            on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
              asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
            }
          :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
          :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
          :async_op.call();
          :is_sync = true;
          return :async_future;
        }
        function test2() → asy::Future<core::bool>
          return self::getNull() as{TypeError,ForDynamic,ForNonNullableByDefault} asy::Future<core::bool>;
        function test3() → core::bool
          return self::getNull() as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool;
        function test4() → asy::Future<core::bool> /* originally async */ {
          final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
          core::bool* :is_sync = false;
          FutureOr<core::bool>? :return_value;
          (dynamic) → dynamic :async_op_then;
          (core::Object, core::StackTrace) → dynamic :async_op_error;
          core::int :await_jump_var = 0;
          dynamic :await_ctx_var;
          dynamic :saved_try_context_var0;
          FutureOr<core::bool>:async_temporary_0;
          function :async_op([dynamic :result, dynamic :exception, dynamic :stack_trace]) → dynamic yielding 
            try {
              #L8:
              {
                [yield] let dynamic #t17 = asy::_awaitHelper(self::getFutureNull(), :async_op_then, :async_op_error, :async_op) in null;
                final FutureOr<core::bool>#t18 = :result as{TypeError,ForDynamic,ForNonNullableByDefault} FutureOr<core::bool>;
                if(#t18 is asy::Future<core::bool>) {
                  [yield] let dynamic #t19 = asy::_awaitHelper(#t18, :async_op_then, :async_op_error, :async_op) in null;
                  :async_temporary_0 = _in::unsafeCast<core::bool>(:result);
                }
                else {
                  :async_temporary_0 = #t18;
                }
                :return_value = :async_temporary_0;
                break #L8;
              }
              asy::_completeOnAsyncReturn(:async_future, :return_value, :is_sync);
              return;
            }
            on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
              asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
            }
          :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
          :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
          :async_op.call();
          :is_sync = true;
          return :async_future;
        }
        function test5() → asy::Future<core::bool>
          return let final<BottomType> #t20 = invalid-expression "pkg/front_end/testcases/nnbd/issue41437a.dart:27:27: Error: A value of type 'Future<dynamic>' can't be returned from a function with return type 'Future<bool>'.
 - 'Future' is from 'dart:async'.
  Future<bool> test5() => getFutureNull(); // error
                          ^" in self::getFutureNull() as{TypeError,ForNonNullableByDefault} asy::Future<core::bool>;
        function test6() → asy::Future<core::bool>
          return self::getFutureBool();
        function test7() → asy::Future<core::bool> /* originally async */ {
          final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
          core::bool* :is_sync = false;
          FutureOr<core::bool>? :return_value;
          (dynamic) → dynamic :async_op_then;
          (core::Object, core::StackTrace) → dynamic :async_op_error;
          core::int :await_jump_var = 0;
          dynamic :await_ctx_var;
          dynamic :saved_try_context_var0;
          FutureOr<core::bool>:async_temporary_0;
          function :async_op([dynamic :result, dynamic :exception, dynamic :stack_trace]) → dynamic yielding 
            try {
              #L9:
              {
                final asy::Future<core::bool> #t21 = self::getFutureBool();
                if(#t21 is asy::Future<core::bool>) {
                  [yield] let dynamic #t22 = asy::_awaitHelper(#t21, :async_op_then, :async_op_error, :async_op) in null;
                  :async_temporary_0 = _in::unsafeCast<core::bool>(:result);
                }
                else {
                  :async_temporary_0 = #t21;
                }
                :return_value = :async_temporary_0;
                break #L9;
              }
              asy::_completeOnAsyncReturn(:async_future, :return_value, :is_sync);
              return;
            }
            on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
              asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
            }
          :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
          :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
          :async_op.call();
          :is_sync = true;
          return :async_future;
        }
        asy::Future<core::bool> var1 = let final<BottomType> #t23 = invalid-expression "pkg/front_end/testcases/nnbd/issue41437a.dart:31:52: Error: A value of type 'Future<dynamic>' can't be assigned to a variable of type 'Future<bool>'.
 - 'Future' is from 'dart:async'.
  Future<bool> var1 = (() async => await getNull())(); // error
                                                   ^" in (() → asy::Future<dynamic> /* originally async */ {
          final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
          core::bool* :is_sync = false;
          FutureOr<dynamic>? :return_value;
          (dynamic) → dynamic :async_op_then;
          (core::Object, core::StackTrace) → dynamic :async_op_error;
          core::int :await_jump_var = 0;
          dynamic :await_ctx_var;
          dynamic :saved_try_context_var0;
          FutureOr<dynamic>:async_temporary_0;
          function :async_op([dynamic :result, dynamic :exception, dynamic :stack_trace]) → dynamic yielding 
            try {
              #L10:
              {
                [yield] let dynamic #t24 = asy::_awaitHelper(self::getNull(), :async_op_then, :async_op_error, :async_op) in null;
                final dynamic #t25 = :result;
                if(#t25 is asy::Future<dynamic>) {
                  [yield] let dynamic #t26 = asy::_awaitHelper(#t25, :async_op_then, :async_op_error, :async_op) in null;
                  :async_temporary_0 = :result;
                }
                else {
                  :async_temporary_0 = #t25;
                }
                :return_value = :async_temporary_0;
                break #L10;
              }
              asy::_completeOnAsyncReturn(:async_future, :return_value, :is_sync);
              return;
            }
            on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
              asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
            }
          :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
          :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
          :async_op.call();
          :is_sync = true;
          return :async_future;
        }).call() as{TypeError,ForNonNullableByDefault} asy::Future<core::bool>;
        asy::Future<core::bool> var2 = (() → dynamic => self::getNull()).call() as{TypeError,ForDynamic,ForNonNullableByDefault} asy::Future<core::bool>;
        core::bool var3 = (() → dynamic => self::getNull()).call() as{TypeError,ForDynamic,ForNonNullableByDefault} core::bool;
        asy::Future<core::bool> var4 = let final<BottomType> #t27 = invalid-expression "pkg/front_end/testcases/nnbd/issue41437a.dart:34:58: Error: A value of type 'Future<dynamic>' can't be assigned to a variable of type 'Future<bool>'.
 - 'Future' is from 'dart:async'.
  Future<bool> var4 = (() async => await getFutureNull())(); // error
                                                         ^" in (() → asy::Future<dynamic> /* originally async */ {
          final asy::_Future<dynamic> :async_future = new asy::_Future::•<dynamic>();
          core::bool* :is_sync = false;
          FutureOr<dynamic>? :return_value;
          (dynamic) → dynamic :async_op_then;
          (core::Object, core::StackTrace) → dynamic :async_op_error;
          core::int :await_jump_var = 0;
          dynamic :await_ctx_var;
          dynamic :saved_try_context_var0;
          FutureOr<dynamic>:async_temporary_0;
          function :async_op([dynamic :result, dynamic :exception, dynamic :stack_trace]) → dynamic yielding 
            try {
              #L11:
              {
                [yield] let dynamic #t28 = asy::_awaitHelper(self::getFutureNull(), :async_op_then, :async_op_error, :async_op) in null;
                final dynamic #t29 = :result;
                if(#t29 is asy::Future<dynamic>) {
                  [yield] let dynamic #t30 = asy::_awaitHelper(#t29, :async_op_then, :async_op_error, :async_op) in null;
                  :async_temporary_0 = :result;
                }
                else {
                  :async_temporary_0 = #t29;
                }
                :return_value = :async_temporary_0;
                break #L11;
              }
              asy::_completeOnAsyncReturn(:async_future, :return_value, :is_sync);
              return;
            }
            on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
              asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
            }
          :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
          :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
          :async_op.call();
          :is_sync = true;
          return :async_future;
        }).call() as{TypeError,ForNonNullableByDefault} asy::Future<core::bool>;
        asy::Future<core::bool> var5 = let final<BottomType> #t31 = invalid-expression "pkg/front_end/testcases/nnbd/issue41437a.dart:35:46: Error: A value of type 'Future<dynamic>' can't be assigned to a variable of type 'Future<bool>'.
 - 'Future' is from 'dart:async'.
  Future<bool> var5 = (() => getFutureNull())(); // error
                                             ^" in (() → asy::Future<dynamic> => self::getFutureNull()).call() as{TypeError,ForNonNullableByDefault} asy::Future<core::bool>;
        asy::Future<core::bool> var6 = (() → asy::Future<core::bool> => self::getFutureBool()).call();
        asy::Future<core::bool> var7 = (() → asy::Future<core::bool> /* originally async */ {
          final asy::_Future<core::bool> :async_future = new asy::_Future::•<core::bool>();
          core::bool* :is_sync = false;
          FutureOr<core::bool>? :return_value;
          (dynamic) → dynamic :async_op_then;
          (core::Object, core::StackTrace) → dynamic :async_op_error;
          core::int :await_jump_var = 0;
          dynamic :await_ctx_var;
          dynamic :saved_try_context_var0;
          FutureOr<dynamic>:async_temporary_0;
          function :async_op([dynamic :result, dynamic :exception, dynamic :stack_trace]) → dynamic yielding 
            try {
              #L12:
              {
                final asy::Future<core::bool> #t32 = self::getFutureBool();
                if(#t32 is asy::Future<core::bool>) {
                  [yield] let dynamic #t33 = asy::_awaitHelper(#t32, :async_op_then, :async_op_error, :async_op) in null;
                  :async_temporary_0 = _in::unsafeCast<core::bool>(:result);
                }
                else {
                  :async_temporary_0 = #t32;
                }
                :return_value = :async_temporary_0;
                break #L12;
              }
              asy::_completeOnAsyncReturn(:async_future, :return_value, :is_sync);
              return;
            }
            on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
              asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
            }
          :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
          :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
          :async_op.call();
          :is_sync = true;
          return :async_future;
        }).call();
      }
      asy::_completeOnAsyncReturn(:async_future, :return_value, :is_sync);
      return;
    }
    on dynamic catch(dynamic exception, core::StackTrace stack_trace) {
      asy::_completeOnAsyncError(:async_future, exception, stack_trace, :is_sync);
    }
  :async_op_then = asy::_asyncThenWrapperHelper(:async_op);
  :async_op_error = asy::_asyncErrorWrapperHelper(:async_op);
  :async_op.call();
  :is_sync = true;
  return :async_future;
}
static method main() → dynamic {}