debugValidateChild method

bool debugValidateChild (RenderObject child)

Checks whether the given render object has the correct runtimeType to be a child of this render object.

Does nothing if assertions are disabled.

Always returns true.

Implementation 

bool debugValidateChild(RenderObject child) {
  assert(() {
    if (child is! ChildType) {
      throw FlutterError(
        'A $runtimeType expected a child of type $ChildType but received a '
        'child of type ${child.runtimeType}.\n'
        'RenderObjects expect specific types of children because they '
        'coordinate with their children during layout and paint. For '
        'example, a RenderSliver cannot be the child of a RenderBox because '
        'a RenderSliver does not understand the RenderBox layout protocol.\n'
        '\n'
        'The $runtimeType that expected a $ChildType child was created by:\n'
        '  $debugCreator\n'
        '\n'
        'The ${child.runtimeType} that did not match the expected child type '
        'was created by:\n'
        '  ${child.debugCreator}\n'
      );
    }
    return true;
  }());
  return true;
}