src/Pipeline/Pipeline.php
protected function getConnection()
    {
        $connection = $this->getClient()->getConnection();

        if ($connection instanceof ReplicationInterface) {
            $connection->switchToMaster();
        }

        return $connection;
    }
protected function getConnection()
    {
        $connection = $this->getClient()->getConnection();

        if ($connection instanceof ReplicationInterface) {
            $connection->switchToMaster();
        }

        return $connection;
    }
Returns the underlying connection to be used by the pipeline.

@return ConnectionInterface