anchor.diff:    const PrimaryKeyJoinColumns(this.joinColumns);
   }
   
  -/** Used to supply a query property or hint to the [NamedQuery] and
  - * [NamedNativeQuery].
  - *
  - *  + [name] - name of the hint.
  - *  + [value] - value of the hint.
  - */
  +/// Used to supply a query property or hint to the [NamedQuery] and
  +/// [NamedNativeQuery].
  +///
  +///  + [name] - name of the hint.
  +///  + [value] - value of the hint.
   class QueryHint {
     final String name;
     final String value;
  
positive.code:   const PrimaryKeyJoinColumn({this.name, this.referencedColumnName, this.columnDefinition});
  }
  
  /** For class/field/method: spcifies group of PrimaryKeyJoinColumn for composite
   * foreign keys.
   *
   * + [joinColumns] - group of [PrimaryKeyJoinColumn].
   */
  //@Target(value:{"METHOD","TYPE","FIELD")
  class PrimaryKeyJoinColumns {
    final List<PrimaryKeyJoinColumn> joinColumns;
  
negative.code:   const Entity([this.name]);
  }
  
  /// For class: specifies the callback listeners classes to be used for an
  /// entity or mapped superclass.
  //@Target(value:"TYPE")
  class EntityListeners {
    final List<String> classes;
  