protected static function _findFilters() {
		$self = static::_object();
		$_query = $self->_query;

		return array(
			'first' => function($self, $params, $chain) {
				$params['options']['limit'] = 1;
				$data = $chain->next($self, $params, $chain);
				$data = is_object($data) ? $data->rewind() : $data;
				return $data ?: null;
			},
			'list' => function($self, $params, $chain) {
				$result = array();
				$meta = $self::meta();
				$name = $meta['key'];

				foreach ($chain->next($self, $params, $chain) as $entity) {
					$key = $entity->{$name};
					$result[is_scalar($key) ? $key : (string) $key] = $entity->{$meta['title']};
				}
				return $result;
			},
			'count' => function($self, $params) use ($_query) {
				$model = $self;
				$type = $params['type'];
				$options = array_diff_key($params['options'], $_query);

				if ($options && !isset($params['options']['conditions'])) {
					$options = array('conditions' => $options);
				} else {
					$options = $params['options'];
				}
				$options += array('type' => 'read') + compact('model');
				$query = $self::invokeMethod('_instance', array('query', $options));
				return $self::connection()->calculation('count', $query, $options);
			}
		);
	}