text: var assert = function (result, expected, message = "") {
    if (result !== expected) {
      throw new Error('Error in assert. Expected "' + expected + '" but was "' + result + '":' + message );
    }
  };
  
  let error = false; 
  
  async function * foo(value = obj) {
      yield '1';
      return 'end';
  }
  
  try {
      var f = foo();
  } catch(e) {
      error = e instanceof ReferenceError;
  }
  
  assert(error, true, 'Error in arguments declaration should to error during evaluation of async generator.');