Source

List<Parameter> get parameters {
  if (!canHaveParameters) {
    throw new StateError("$element cannot have parameters");
  }

  if (_parameters != null) return _parameters;

  List<ParameterElement> params;

  if (element is ExecutableElement) {
    // the as check silences the warning
    params = (element as ExecutableElement).parameters;
  }

  if (element is FunctionTypeAliasElement) {
    params = (element as FunctionTypeAliasElement).parameters;
  }

  _parameters = new UnmodifiableListView<Parameter>(params
      .map((p) => new ModelElement.from(p, library))
      .toList() as Iterable<Parameter>);

  return _parameters;
}