wikimedia/mediawiki-extensions-MobileFrontend

/**
 * Extends a class with new methods and member properties.
 *
 * @ignore
 * @param {Function} Child function
 * @param {Object|Function} ParentOrPrototype class to inherit from
 *  OR if no inheriting class a prototype to extend the class with
 * @param {Object} [prototype]
 */
module.exports = function mfExtend( Child, ParentOrPrototype, prototype ) {
    let key;
    if ( prototype ) {
        OO.inheritClass( Child, ParentOrPrototype );
    } else {
        OO.initClass( Child );
        prototype = ParentOrPrototype;
    }
    for ( key in prototype ) {
        Child.prototype[key] = prototype[key];
    }
};