function append(parent, child) {
            if (parent.el !== undefined && child.el !== undefined) {
                parent.el.appendChild(child.el);
            }
        }
function append(parent, child) {
            if (parent.el !== undefined && child.el !== undefined) {
                parent.el.appendChild(child.el);
            }
        }
function append ( parent , child ) { if ( parent . el !== undefined && child . el !== undefined ) { parent . el . appendChild ( child . el ) ; } }
Insert element to the end of parent childs  @method append @param {dom.Element} parent @param {dom.Element} child
Insert element to the end of parent childs