library;
import self as self;
import "dart:core" as core;
import "dart:async" as asy;

import "dart:async";

static method f() → FutureOr<core::Iterable<core::int>> sync* /* emittedValueType= core::int */ {
  yield("Hello!" as dynamic) as{TypeError,ForDynamic} core::int;
}
static method g() → FutureOr<asy::Stream<core::int>> async* /* emittedValueType= core::int */ {
  yield*("Hello!" as dynamic) as{TypeError,ForDynamic} asy::Stream<core::int>;
}
static method main() → dynamic async /* emittedValueType= dynamic */ {
  FutureOr<core::Iterable<core::int>>iterable = self::f();
  if(iterable is asy::Future<core::Object?>)
    return;
  self::expectThrows(() → Null {
    core::int i = iterable{core::Iterable<core::int>}.{core::Iterable::first}{core::int};
  });
  FutureOr<asy::Stream<core::int>>stream = self::g();
  if(stream is asy::Future<core::Object?>)
    return;
  await self::expectAsyncThrows(() → asy::Future<Null> async /* emittedValueType= Null */ {
    core::int i = await stream{asy::Stream<core::int>}.{asy::Stream::first}{asy::Future<core::int>};
  }) /* runtimeCheckType= asy::Future<dynamic> */ ;
}
static method expectThrows(dynamic f) → dynamic {
  core::bool hasThrown = true;
  try {
    f{dynamic}();
    hasThrown = false;
  }
  on core::Object catch(final core::Object e) {
  }
  if(!hasThrown) {
    throw "Expected the function to throw.";
  }
}
static method expectAsyncThrows(dynamic f) → dynamic async /* emittedValueType= dynamic */ {
  core::bool hasThrown = true;
  try {
    await f{dynamic}() /* runtimeCheckType= asy::Future<dynamic> */ ;
    hasThrown = false;
  }
  on core::Object catch(final core::Object e) {
  }
  if(!hasThrown) {
    throw "Expected the function to throw.";
  }
}