docs: def union(self, *others):
          r"""Return a new multiset with all elements from the multiset and the others with maximal multiplicities.
  
          >>> ms = Multiset('aab')
          >>> sorted(ms.union('bc'))
          ['a', 'a', 'b', 'c']
  
          You can also use the ``|`` operator for the same effect. However, the operator version
          will only accept a set as other operator, not any iterable, to avoid errors.
  
          >>> ms = Multiset('aab')
          >>> sorted(ms | Multiset('aaa'))
          ['a', 'a', 'a', 'b']
  
          For a variant of the operation which modifies the multiset in place see
          :meth:`union_update`.
  
          Args:
              *others: The other sets to union the multiset with. Can also be any :class:`~typing.Iterable`\[~T]
                  or :class:`~typing.Mapping`\[~T, :class:`int`] which are then converted to :class:`Multiset`\[~T].
  
          Returns:
              The multiset resulting from the union.
          """
          result = self.__copy__()
          _elements = result._elements
          _total = result._total
          for other in map(self._as_mapping, others):
              for element, multiplicity in other.items():
                  old_multiplicity = _elements.get(element, 0)
                  if multiplicity > old_multiplicity:
                      _elements[element] = multiplicity
                      _total += multiplicity - old_multiplicity
          result._total = _total
          return result