private Token CreateToken(IProjectNode node, TokenType type, string text, int offset, int length)
 {
     Token t = new Token(node, type, text, offset, length, m_lineNumber);
     m_Tokens.Add(t);
     return t;
 }
 public void RollBackToken(Token token)
 {
     m_Offset = token.Offset;
     m_Tokens.Remove(token);
 }