code: def t_heredoc_END_HEREDOC(t):
      r'(?<=\n)[A-Za-z_][\w_]*'
      if t.value == t.lexer.heredoc_label:
          del t.lexer.heredoc_label
          t.lexer.pop_state()
      else:
          t.type = 'ENCAPSED_AND_WHITESPACE'
      return f t_heredoc_END_HEREDOC(t):
      r'(?<=\n)[A-Za-z_][\w_]*'
      if t.value == t.lexer.heredoc_label:
          del t.lexer.heredoc_label
          t.lexer.pop_state()
      else:
          t.type = 'ENCAPSED_AND_WHITESPACE'
      return t
docs: r'(?<=\n)[A-Za-z_][\w_]*