public SpecialMethodModelImmutable(SpecialMethodModelState state)
     : base(state)
 {
     this._state = state;
 }
 public SpecialMethodModelMutable(SpecialMethodModelState state, SpecialMethodModelImmutable immutable)
     : base(state, immutable)
 {
     this._state     = state;
     this._immutable = immutable;
 }