def _create_connection(self):
        """.. :py:method::

              If we hava several hosts, we can random choice one to connect
        """
        db = psycopg2.connect(database=self.dbname,
                                user=self.user, password=self.password,
                                host=self.host, port=self.port)
        if 'psycopg2.extras' in sys.modules:
            psycopg2.extras.register_hstore(db)
        return db
.. :py:method::

              If we hava several hosts, we can random choice one to connect