docs: def __left_merge(multicolor1, multicolor2):
          """ Updates first supplied :class:`Multicolor` instance with information from second supplied :class:`Multicolor` instance.
  
          First supplied instances attribute :attr:`Multicolor.multicolors` is updated with a help of ``+`` method of python Counter object.
  
          :param multicolor1: instance to update information in
          :type multicolor1: :class:`Multicolor`
          :param multicolor2: instance to use information for update from
          :type multicolor2: :class:`Multicolor`
          :return: updated first supplied :class:`Multicolor` instance
          :rtype: :class:`Multicolor`
          """
          multicolor1.multicolors = multicolor1.multicolors + multicolor2.multicolors
          return multicolor1