src/Connection/Replication/SentinelReplication.php
public function switchTo(NodeConnectionInterface $connection)
    {
        if ($connection && $connection === $this->current) {
            return;
        }

        if ($connection !== $this->master && !in_array($connection, $this->slaves, true)) {
            throw new \InvalidArgumentException('Invalid connection or connection not found.');
        }

        $connection->connect();

        if ($this->current) {
            $this->current->disconnect();
        }

        $this->current = $connection;
    }
public function switchTo(NodeConnectionInterface $connection)
    {
        if ($connection && $connection === $this->current) {
            return;
        }

        if ($connection !== $this->master && !in_array($connection, $this->slaves, true)) {
            throw new \InvalidArgumentException('Invalid connection or connection not found.');
        }

        $connection->connect();

        if ($this->current) {
            $this->current->disconnect();
        }

        $this->current = $connection;
    }
Switches the internal connection in use by the backend.

Sentinel connections are not considered as part of the pool, meaning that
trying to switch to a sentinel will throw an exception.

@param NodeConnectionInterface $connection Connection instance in the pool.