code: public function getConnectionByCommand(CommandInterface $command)
      {
          $connection = $this->getConnectionInternal($command);
  
          if (!$connection->isConnected()) {
              // When we do not have any available slave in the pool we can expect
              // read-only operations to hit the master server.
              $expectedRole = $this->strategy->isReadOperation($command) && $this->slaves ? 'slave' : 'master';
              $this->assertConnectionRole($connection, $expectedRole);
          }
  
          return $connection;
      }
docs: {@inheritdoc}