anchor.diff:  
     bool hasError() {
       return error;
  +  }
  +
  +  void set errorMessage(String err) {
  +    this._errorMessage = err;
  +  }
  +
  +  String get errorMessage {
  +    return _customErrorMessage != null ? _customErrorMessage : _errorMessage;
     }
   
     FnxInputComponent get component => _component;
  
positive.code:   handleErrorChange(dynamic errorStatus) {
      if (errorStatus is bool) {
        this.error = errorStatus;
      }
    }
  }
  
  abstract class FnxInputComponent implements OnInit {
  
    final FnxInput _wrapper;
  
    final String _privComponentId = ui.uid("comp_");
  
    final EventEmitter errorStateChange = new EventEmitter();
  
    FnxInputComponent(this._wrapper);
  
    String get componentId {
      if (_wrapper != null) {
  
negative.code: 
  
    @Input() String label;
    String _errorMessage;
    String _customErrorMessage;
  
    bool error = false;
  
  