public function filters(array $filters = array()) {
		if ($this->_filters && !$filters) {
			return $this->_filters;
		}
		$filters += (array) $this->_config['filters'];
		$results = array();

		foreach ($filters as $filter => $options) {
			if (!$class = Libraries::locate('test.filter', $filter)) {
				throw new ClassNotFoundException("`{$class}` is not a valid test filter.");
			}
			$options['name'] = strtolower(join('', array_slice(explode("\\", $class), -1)));
			$results[$class] = $options + array('apply' => array(), 'analyze' => array());
		}
		return $this->_filters = $results;
	}