wikimedia / mediawiki

			'templateOverridesByCluster', 'templateOverridesBySection', 'masterTemplateOverrides',

			'readOnlyBySection', 'loadMonitorClass' ];

		foreach ( $required as $key ) {

			if ( !isset( $conf[$key] ) ) {

				throw new InvalidArgumentException( __CLASS__ . ": $key is required." );

			}

			$this->$key = $conf[$key];

		}

		foreach ( $optional as $key ) {

			if ( isset( $conf[$key] ) ) {

		$this->backend = $backend;

		$this->logger = $logger;

		list( $required, $optional, $paths ) = $this->allowedParams();

		foreach ( $required as $name ) {

			if ( isset( $params[$name] ) ) {

				$this->params[$name] = $params[$name];

			} else {

				throw new InvalidArgumentException( "File operation missing parameter '$name'." );

			}

		}

		foreach ( $optional as $name ) {

			if ( isset( $params[$name] ) ) {

				$this->params[$name] = $params[$name];