Base::getIndices

protected function getIndices();

/**
 * Check is available filter in filters list of provider.
 *
 * @param string $filterKey Needle filter key.
 * @return bool
 */
private function isAvailableFilter($filterKey)
{
	$availableFilterKeys = $this->availableFilterKeys();

	return in_array($filterKey, $availableFilterKeys);
}