public function setDriver($driver_name)
	{
		if ( !is_string($driver_name) ) {
			throw new \InvalidArgumentException('The Mink driver name must be a string');
		}

		$this->_driverFactory = $this->_driverFactoryRegistry->get($driver_name);
		$this->_mergedDefaults = self::arrayMergeRecursive($this->defaults, $this->_driverFactory->getDriverDefaults());

		return $this->setParameter('driver', $driver_name);
	}