'Adds a :class:`~pymongo.collation.Collation` to this query.
This option is only supported on MongoDB 3.4 and above.
Raises :exc:`TypeError` if `collation` is not an instance of
:class:`~pymongo.collation.Collation` or a ``dict``. Raises
:exc:`~pymongo.errors.InvalidOperation` if this :class:`Cursor` has
already been used. Only the last collation applied to this cursor has
any effect.
:Parameters:
- `collation`: An instance of :class:`~pymongo.collation.Collation`.'

def collation(self, collation):

    self.__check_okay_to_chain()
    self.__collation = validate_collation_or_none(collation)
    return self
