@timeout
    @defer.inlineCallbacks
    def collection_names(self, **kwargs):
        results = yield self["system.namespaces"].find(**kwargs)

        names = [r["name"] for r in results]
        names = [n[len(str(self)) + 1:] for n in names
                 if n.startswith(str(self) + ".")]
        names = [n for n in names if n not in "$"]
        defer.returnValue(names)
dataset/ETHPy150Open twisted/txmongo/txmongo/database.py/Database.collection_names/swapped operands of `not in`