anchor.diff:      updatePropertiesFromNodes(attrs: ["disabled", "name", "max_length"], invoke_callbacks: true);
     }
   
  -  @override
  -  set value(v) {
  +  /** This method is reloaded (from FormFieldComponent) to make sure
  +    * we only allow digits and period (.) in to be entered into the field.
  +    * If a user enters some other character it is immediately erased.
  +    *
  +    * Additionally, it makes sure the length of the field does not exceed
  +    * the value in the #max_length property.
  +    */
  +  @override set value(v) {
   
       if(v is String) {
   
  
positive.code:     }
    }
  
    @override
    void prvt_updateValueFromDom() {
      this.value = value_holder_element.value;
    }
  
  
negative.code: part of nest_ui;
  
  /** Numeric field can only contain digits and a period (.) character.
    * All other characters are automatically erased.
    */
  class NumericFormFieldComponent extends FormFieldComponent {
  
    List attribute_names = ["validation_errors_summary", "name", "disabled", "max_length"];
  