code: def is_symbols_pair_complete(editor, symbol):
      
  
      symbols_pairs = get_editor_capability(editor, "symbols_pairs")
      if not symbols_pairs:
          return
  
      cursor = editor.textCursor()
      cursor.movePosition(QTextCursor.StartOfLine, QTextCursor.MoveAnchor)
      cursor.movePosition(QTextCursor.EndOfLine, QTextCursor.KeepAnchor)
      selected_text = foundations.strings.to_string(cursor.selectedText())
      if symbol == symbols_pairs[symbol]:
          return selected_text.count(symbol) % 2 == 0
      else:
          return selected_text.count(symbol) == selected_text.count(symbols_pairs[symbol])
docs: Returns if the symbols pair is complete on current editor line.
  
      :param editor: Document editor.
      :type editor: QWidget
      :param symbol: Symbol to check.
      :type symbol: unicode
      :return: Is symbols pair complete.
      :rtype: bool