| library; | 
 | // | 
 | // Problems in library: | 
 | // | 
 | // pkg/front_end/testcases/nnbd/nullable_receiver.dart:20:5: Error: Property 'length' cannot be accessed on 'String?' because it is potentially null. | 
 | // Try accessing using ?. instead. | 
 | //   s.length; | 
 | //     ^^^^^^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd/nullable_receiver.dart:21:5: Error: Method 'substring' cannot be called on 'String?' because it is potentially null. | 
 | // Try calling using ?. instead. | 
 | //   s.substring(1, 1); | 
 | //     ^^^^^^^^^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd/nullable_receiver.dart:23:5: Error: Method 'foo' cannot be called on 'A?' because it is potentially null. | 
 | //  - 'A' is from 'pkg/front_end/testcases/nnbd/nullable_receiver.dart'. | 
 | // Try calling using ?. instead. | 
 | //   a.foo(); | 
 | //     ^^^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd/nullable_receiver.dart:24:5: Error: Property 'bar' cannot be accessed on 'A?' because it is potentially null. | 
 | //  - 'A' is from 'pkg/front_end/testcases/nnbd/nullable_receiver.dart'. | 
 | // Try accessing using ?. instead. | 
 | //   a.bar; | 
 | //     ^^^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd/nullable_receiver.dart:25:5: Error: Property 'baz' cannot be accessed on 'A?' because it is potentially null. | 
 | //  - 'A' is from 'pkg/front_end/testcases/nnbd/nullable_receiver.dart'. | 
 | // Try accessing using ?. instead. | 
 | //   a.baz = 42; | 
 | //     ^^^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd/nullable_receiver.dart:26:4: Error: Can't use an expression of type 'A?' as a function because it's potentially null. | 
 | //  - 'A' is from 'pkg/front_end/testcases/nnbd/nullable_receiver.dart'. | 
 | // Try calling using ?.call instead. | 
 | //   a(); | 
 | //    ^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd/nullable_receiver.dart:27:13: Error: Too many positional arguments: 0 allowed, but 1 found. | 
 | // Try removing the extra positional arguments. | 
 | //   b.toString(0); | 
 | //             ^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd/nullable_receiver.dart:29:17: Error: Can't tear off method 'call' from a potentially null value. | 
 | //   Function f1 = a; | 
 | //                 ^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd/nullable_receiver.dart:30:24: Error: Can't tear off method 'call' from a potentially null value. | 
 | //   void Function() f2 = a; | 
 | //                        ^ | 
 | // | 
 | // pkg/front_end/testcases/nnbd/nullable_receiver.dart:31:25: Error: Can't tear off method 'call' from a potentially null value. | 
 | //   void Function()? f3 = a; | 
 | //                         ^ | 
 | // | 
 | import self as self; | 
 | import "dart:core" as core; | 
 |  | 
 | class A extends core::Object { | 
 |   synthetic constructor •() → self::A | 
 |     : super core::Object::•() | 
 |     ; | 
 |   method foo() → dynamic {} | 
 |   get bar() → core::int | 
 |     return 42; | 
 |   set baz(core::int value) → void {} | 
 |   method call() → void {} | 
 | } | 
 | class B extends core::Object { | 
 |   synthetic constructor •() → self::B | 
 |     : super core::Object::•() | 
 |     ; | 
 |   method toString([core::int extra = #C1]) → core::String | 
 |     return super.{core::Object::toString}(); | 
 | } | 
 | static method error(core::String? s, self::A? a, self::B? b) → dynamic { | 
 |   invalid-expression "pkg/front_end/testcases/nnbd/nullable_receiver.dart:20:5: Error: Property 'length' cannot be accessed on 'String?' because it is potentially null. | 
 | Try accessing using ?. instead. | 
 |   s.length; | 
 |     ^^^^^^" in s.{core::String::length}{<nullable>}.{core::int}; | 
 |   invalid-expression "pkg/front_end/testcases/nnbd/nullable_receiver.dart:21:5: Error: Method 'substring' cannot be called on 'String?' because it is potentially null. | 
 | Try calling using ?. instead. | 
 |   s.substring(1, 1); | 
 |     ^^^^^^^^^" in s.{core::String::substring}{<nullable>}.(1, 1){(core::int, [core::int?]) → core::String}; | 
 |   invalid-expression "pkg/front_end/testcases/nnbd/nullable_receiver.dart:23:5: Error: Method 'foo' cannot be called on 'A?' because it is potentially null. | 
 |  - 'A' is from 'pkg/front_end/testcases/nnbd/nullable_receiver.dart'. | 
 | Try calling using ?. instead. | 
 |   a.foo(); | 
 |     ^^^" in a.{self::A::foo}{<nullable>}.(){() → dynamic}; | 
 |   invalid-expression "pkg/front_end/testcases/nnbd/nullable_receiver.dart:24:5: Error: Property 'bar' cannot be accessed on 'A?' because it is potentially null. | 
 |  - 'A' is from 'pkg/front_end/testcases/nnbd/nullable_receiver.dart'. | 
 | Try accessing using ?. instead. | 
 |   a.bar; | 
 |     ^^^" in a.{self::A::bar}{<nullable>}.{core::int}; | 
 |   invalid-expression "pkg/front_end/testcases/nnbd/nullable_receiver.dart:25:5: Error: Property 'baz' cannot be accessed on 'A?' because it is potentially null. | 
 |  - 'A' is from 'pkg/front_end/testcases/nnbd/nullable_receiver.dart'. | 
 | Try accessing using ?. instead. | 
 |   a.baz = 42; | 
 |     ^^^" in a.{self::A::baz}{<nullable>}. = 42; | 
 |   invalid-expression "pkg/front_end/testcases/nnbd/nullable_receiver.dart:26:4: Error: Can't use an expression of type 'A?' as a function because it's potentially null. | 
 |  - 'A' is from 'pkg/front_end/testcases/nnbd/nullable_receiver.dart'. | 
 | Try calling using ?.call instead. | 
 |   a(); | 
 |    ^" in a.{self::A::call}{<nullable>}.(){() → void}; | 
 |   invalid-expression "pkg/front_end/testcases/nnbd/nullable_receiver.dart:27:13: Error: Too many positional arguments: 0 allowed, but 1 found. | 
 | Try removing the extra positional arguments. | 
 |   b.toString(0); | 
 |             ^" in b.{core::Object::toString}{<inapplicable>}.(0){(invalid-type) → invalid-type}; | 
 |   core::Function f1 = invalid-expression "pkg/front_end/testcases/nnbd/nullable_receiver.dart:29:17: Error: Can't tear off method 'call' from a potentially null value. | 
 |   Function f1 = a; | 
 |                 ^" in a as{TypeError} core::Function; | 
 |   () → void f2 = invalid-expression "pkg/front_end/testcases/nnbd/nullable_receiver.dart:30:24: Error: Can't tear off method 'call' from a potentially null value. | 
 |   void Function() f2 = a; | 
 |                        ^" in a as{TypeError} () → void; | 
 |   () →? void f3 = invalid-expression "pkg/front_end/testcases/nnbd/nullable_receiver.dart:31:25: Error: Can't tear off method 'call' from a potentially null value. | 
 |   void Function()? f3 = a; | 
 |                         ^" in a as{TypeError} () →? void; | 
 | } | 
 | static method ok<T extends core::Object?>(core::String? s, self::A? a, self::ok::T% t, self::B? b, core::Invocation i) → dynamic { | 
 |   s =={core::String::==}{(core::Object) → core::bool} s; | 
 |   a =={core::Object::==}{(core::Object) → core::bool} a; | 
 |   t =={core::Object::==}{(core::Object) → core::bool} t; | 
 |   b =={core::Object::==}{(core::Object) → core::bool} b; | 
 |   s.{core::Object::hashCode}{<object>}.{core::int}; | 
 |   a.{core::Object::hashCode}{<object>}.{core::int}; | 
 |   t.{core::Object::hashCode}{<object>}.{core::int}; | 
 |   b.{core::Object::hashCode}{<object>}.{core::int}; | 
 |   s.{core::Object::toString}{<object>}.(){() → core::String}; | 
 |   a.{core::Object::toString}{<object>}.(){() → core::String}; | 
 |   t.{core::Object::toString}{<object>}.(){() → core::String}; | 
 |   b.{core::Object::toString}{<object>}.(){() → core::String}; | 
 |   try { | 
 |     s.{core::Object::noSuchMethod}{<object>}.(i){(core::Invocation) → dynamic}; | 
 |   } | 
 |   on core::Object catch(final core::Object e, final core::StackTrace t) { | 
 |   } | 
 |   try { | 
 |     a.{core::Object::noSuchMethod}{<object>}.(i){(core::Invocation) → dynamic}; | 
 |   } | 
 |   on core::Object catch(final core::Object e, final core::StackTrace t) { | 
 |   } | 
 |   try { | 
 |     t.{core::Object::noSuchMethod}{<object>}.(i){(core::Invocation) → dynamic}; | 
 |   } | 
 |   on core::Object catch(final core::Object e, final core::StackTrace t) { | 
 |   } | 
 |   try { | 
 |     b.{core::Object::noSuchMethod}{<object>}.(i){(core::Invocation) → dynamic}; | 
 |   } | 
 |   on core::Object catch(final core::Object e, final core::StackTrace t) { | 
 |   } | 
 |   s.{core::Object::runtimeType}{<object>}.{core::Type}; | 
 |   a.{core::Object::runtimeType}{<object>}.{core::Type}; | 
 |   t.{core::Object::runtimeType}{<object>}.{core::Type}; | 
 |   b.{core::Object::runtimeType}{<object>}.{core::Type}; | 
 | } | 
 | static method main() → dynamic {} | 
 |  | 
 | constants  { | 
 |   #C1 = 42 | 
 | } |