Function scheme

src/utils/scheme.js:8–14

(arg = EMPTY)

 * @returns {boolean} True if the string contains a slash or starts with URI scheme character
 */
export function scheme (arg = EMPTY) {
	if (arg === null || arg === undefined) {
		arg = EMPTY;
	}

	return arg.includes(SLASH) || arg.startsWith(URI_SCHEME) || arg.startsWith(":");
}