def update(self, *others):
        r"""Like :meth:`dict.update` but add multiplicities instead of replacing them.

        >>> ms = Multiset('aab')
        >>> ms.update('abc')
        >>> sorted(ms)
        ['a', 'a', 'a', 'b', 'b', 'c']

        Note that the operator ``+=`` is equivalent to :meth:`update`, except that the operator will only
        accept sets to avoid accidental errors.

        >>> ms += Multiset('bc')
        >>> sorted(ms)
        ['a', 'a', 'a', 'b', 'b', 'b', 'c', 'c']

        For a variant of the operation which does not modify the multiset, but returns a new
        multiset instead see :meth:`combine`.

        Args:
            others: The other sets to add to this multiset. Can also be any :class:`~typing.Iterable`\[~T]
                or :class:`~typing.Mapping`\[~T, :class:`int`] which are then converted to :class:`Multiset`\[~T].
        """
        _elements = self._elements
        for other in map(self._as_mapping, others):
            for element, multiplicity in other.items():
                self[element] += multiplicity
r"""Like :meth:`dict.update` but add multiplicities instead of replacing them.

        >>> ms = Multiset('aab')
        >>> ms.update('abc')
        >>> sorted(ms)
        ['a', 'a', 'a', 'b', 'b', 'c']

        Note that the operator ``+=`` is equivalent to :meth:`update`, except that the operator will only
        accept sets to avoid accidental errors.

        >>> ms += Multiset('bc')
        >>> sorted(ms)
        ['a', 'a', 'a', 'b', 'b', 'b', 'c', 'c']

        For a variant of the operation which does not modify the multiset, but returns a new
        multiset instead see :meth:`combine`.

        Args:
            others: The other sets to add to this multiset. Can also be any :class:`~typing.Iterable`\[~T]
                or :class:`~typing.Mapping`\[~T, :class:`int`] which are then converted to :class:`Multiset`\[~T].