public static function get_allowed_protocols() {
		$protocols = array(
			'http',
			'https',
		);

		$protocols = apply_filters('blobmimes_svg_allowed_protocols', $protocols);
		if (!is_array($protocols) || !count($protocols)) {
			return array();
		}

		// Convert to lowercase for easier comparison.
		foreach ($protocols as $k=>$v) {
			$protocols[$k] = mb::strtolower(trim($v));
			if (!strlen($protocols[$k])) {
				unset($protocols[$k]);
			}
		}

		// Pre-sorting will speed up looped checks.
		$protocols = array_unique($protocols);
		sort($protocols);
		return $protocols;
	}