docs: def symbol_pos(self, cursor, character_type=OPEN, symbol_type=PAREN):
          """
          Find the corresponding symbol position (line, column) of the specified
          symbol. If symbol type is PAREN and character_type is OPEN, the
          function will look for '('.
  
          :param cursor: QTextCursor
          :param character_type: character type to look for (open or close char)
          :param symbol_type: symbol type (index in the SYMBOLS map).
          """
          retval = None, None
          original_cursor = self.editor.textCursor()
          self.editor.setTextCursor(cursor)
          block = cursor.block()
          data = get_block_symbol_data(self.editor, block)
          self._match(symbol_type, data, block.position())
          for deco in self._decorations:
              if deco.character == self.SYMBOLS[symbol_type][character_type]:
                  retval = deco.line, deco.column
                  break
          self.editor.setTextCursor(original_cursor)
          self._clear_decorations()
          return retval