How to use the pymongocrypt.binary.MongoCryptBinaryOut function in pymongocrypt

def message(self):
        """The HTTP request message to send to the given endpoint."""
        with MongoCryptBinaryOut() as binary:
            if not lib.mongocrypt_kms_ctx_message(self.__ctx, binary.bin):
                self.__raise_from_status()
            return binary.to_bytes()

def mongo_operation(self):
        """Returns the mongo operation to execute as bson bytes."""
        with MongoCryptBinaryOut() as binary:
            if not lib.mongocrypt_ctx_mongo_op(self.__ctx, binary.bin):
                self._raise_from_status()
            return binary.to_bytes()

def finish(self):
        """Returns the finished mongo operation as bson bytes."""
        with MongoCryptBinaryOut() as binary:
            if not lib.mongocrypt_ctx_finalize(self.__ctx, binary.bin):
                self._raise_from_status()
            return binary.to_bytes()