code: protected function configure()
      {
          $this->slave ? $this->configureMasterSlaveDsn($this->qualifer, $this->dsn, $this->user, $this->password, $this->slave)
              : $this->configureSingleDsn($this->qualifer, $this->dsn, $this->user, $this->password);
      }
docs: {@inheritdoc}