docstr: Close a grouping expression returning the matching position
code: def close_group(self):
      """Close a grouping expression returning the matching position"""
      if self.__group_depth == 0:
          raise ValueError("Unmatched closing parentheses")
      if self.__group_name is not None:
          self.__group_names.append(self.__group_name)
      self.__group_name = None
      self.__group_depth -= 1
      if self.__is_non_grouping:
          self.__group_count += 1
      matching_brace = self.__group_starts.pop()
      self.mark_tokens(1, TOK_GROUP)
      self.matching_braces[self.position] = matching_brace
      self.position += 1
      self.__any_tokens = True
      return matching_brace
  
imports: import re
  import wx
  import wx.stc
label_desc: Use image node_id 4 for calling the RegexpState obj's underlying member method code with example usage: obj.close_group() and returns: matching_brace