anchor.diff:            "Member $name not found${cls != null ? ' in class $cls' : ''}.");
         Expect.equals(
             expectedType,
  -          '${type}',
  +          typeToString(type),
             "Unexpected type for $name"
  -              "${cls != null ? ' in class $cls' : ''}.");
  +          "${cls != null ? ' in class $cls' : ''}.");
         return type;
       }
   
  
positive.code:     ClassEntity C = env.getClass('C');
      DartType futureT = getReturnType('futureT', 'Future<C.T>', C);
      FutureOrType futureOrT = getReturnType('futureOrT', 'FutureOr<C.T>', C);
      DartType T = futureOrT.typeArgument;
      Expect.isTrue(futureOrT.containsTypeVariables);
      futureOrT.forEachTypeVariable((t) => Expect.equals(T, t));
  
      DartType returnVoid = getFunctionType('returnVoid', 'void Function()');
      DartType returnFutureNull =
          getFunctionType('futureOrNull', 'Future<Null> Function()');
  
      List<DartType> all = [
        Object_,
  
negative.code:       FunctionType type = env.getMemberType(name, cls);
        Expect.isNotNull(type,
            "Member $name not found${cls != null ? ' in class $cls' : ''}.");
        DartType returnType = type.returnType.withoutNullability;
        Expect.equals(
            expectedType,
            typeToString(returnType),
            "Unexpected return type for $name"
            "${cls != null ? ' in class $cls' : ''}.");
        return returnType;
      }
  
  