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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 make_datastore_query(self, cursor=None):
 """Returns a datastore.Query that generates all namespaces in the range. Args: cursor: start cursor for the query. Returns: A datastore.Query instance that generates db.Keys for each namespace in the NamespaceRange. """

    filters = {}
    filters['__key__ >= '] = _key_for_namespace(
        self.namespace_start, self.app)
    filters['__key__ <= '] = _key_for_namespace(
        self.namespace_end, self.app)

    return datastore.Query('__namespace__',
                           filters=filters,
                           keys_only=True,
                           cursor=cursor,
                           _app=self.app)