Source

File: wp-includes/Requests/Exception/HTTP.php

public static function get_class($code) {
		if (!$code) {
			return 'Requests_Exception_HTTP_Unknown';
		}

		$class = sprintf('Requests_Exception_HTTP_%d', $code);
		if (class_exists($class)) {
			return $class;
		}

		return 'Requests_Exception_HTTP_Unknown';
	}