public void SetPSourceFile(PSourceFile node)
        {
            if (_base_ != null)
            {
                _base_.Parent(null);
            }

            if (node != null)
            {
                if (node.Parent() != null)
                {
                    node.Parent().RemoveChild(node);
                }

                node.Parent(this);
            }

            _base_ = node;
        }
        internal override void RemoveChild(Node child)
        {
            if (_base_ == child)
            {
                _base_ = null;
                return;
            }

            if (_eof_ == child)
            {
                _eof_ = null;
                return;
            }
        }
 public Start(
     PSourceFile _base_,
     EOF _eof_)
 {
     SetPSourceFile(_base_);
     SetEOF(_eof_);
 }