public function map(array $configuration)
	{

        $defaults = ['pooled' => false];
        $optional = ['servicename', 'instancename'];

        foreach ($optional as $opt) {
            if(isset($configuration[$opt]))
                $defaults[$opt] = $configuration[$opt];
        }

		return array_merge($defaults, [
			'driver' => $this->driver($configuration['driver']),
            'port' => @$configuration['port'] ? $configuration['port'] : 1521,
			'host' => $configuration['host'],
			'dbname' => $configuration['database'],
			'user' => $configuration['username'],
			'password' => $configuration['password'],
            'charset' => $configuration['charset'],
            'prefix' => @$configuration['prefix'] ? $configuration['prefix'] : null
		]);
	}