anchor.diff:  class Test {
     final String code;
     final List<StackTraceLine> expectedLines;
  -
  -  Test(this.code, this.expectedLines);
  +  final List<StackTraceLine> unexpectedLines;
  +
  +  Test(this.code, this.expectedLines, this.unexpectedLines);
   }
   
   const int _LF = 0x0A;
  
positive.code:       "Missing stack trace lines for test:\n${test.code}\n"
        "Actual:\n${dartStackTrace.join('\n')}\n"
        "Expected:\n${test.expectedLines.join('\n')}\n");
  
    print("Deleting '${tmpDir.path}'.");
    tmpDir.deleteSync(recursive: true);
  
negative.code: @NoInline()
  test1() async {
    // This call is no longer on the stack when the error is thrown.
    await @{:test1}test2();
  }
  @NoInline()
  test2() async {
  