Get a connection from the pool

def get_connection(self, command_name, *keys, **options):
        "Get a connection from the pool"
        self._checkpid()
        try:
            connection = self._available_connections.pop()
        except IndexError:
            connection = self.make_connection()
        self._in_use_connections.add(connection)
        try:
            # ensure this connection is connected to Redis
            connection.connect()
            # connections that the pool provides should be ready to send
            # a command. if not, the connection was either returned to the
            # pool before all data has been read or the socket has been
            # closed. either way, reconnect and verify everything is good.
            if not connection.is_ready_for_command():
                connection.disconnect()
                connection.connect()
                if not connection.is_ready_for_command():
                    raise ConnectionError('Connection not ready')
        except:  # noqa: E722
            # release the connection back to the pool so that we don't leak it
            self.release(connection)
            raise

        return connection