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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def count(self, filter=None, **kwargs):
 """Get the number of documents in this collection. All optional count parameters should be passed as keyword arguments to this method. Valid options include: - `hint` (string or list of tuples):
 The index to use. Specify either the index name as a string or the index specification as a list of tuples (e.g. [('a', pymongo.ASCENDING), ('b', pymongo.ASCENDING)]). - `limit` (int):
 The maximum number of documents to count. - `skip` (int):
 The number of matching documents to skip before returning results. - `maxTimeMS` (int):
 The maximum amount of time to allow the count command to run, in milliseconds. - `collation` (optional):
 An instance of :class:`~pymongo.collation.Collation`. This option is only supported on MongoDB 3.4 and above. The :meth:`count` method obeys the :attr:`read_preference` of this :class:`Collection`. :Parameters: - `filter` (optional):
 A query document that selects which documents to count in the collection. - `**kwargs` (optional):
 See list of options above. .. versionchanged:: 3.4 Support the `collation` option. """

        cmd = SON([("count", self.__name)])
        if filter is not None:
            if "query" in kwargs:
                raise ConfigurationError("can't pass both filter and query")
            kwargs["query"] = filter
        if "hint" in kwargs and not isinstance(kwargs["hint"], string_type):
            kwargs["hint"] = helpers._index_document(kwargs["hint"])
        collation = validate_collation_or_none(kwargs.pop('collation', None))
        cmd.update(kwargs)
        return self._count(cmd, collation)