Set the size of a component, element or composite or an array of components or elements.
@param {Ext.Component/Ext.Component[]/Ext.dom.Element/Ext.dom.Element[]/Ext.dom.CompositeElement}
The item(s) to size.
@param {Number} width The new width to set (ignored if undefined or NaN).
@param {Number} height The new height to set (ignored if undefined or NaN).
function(item, width, height) {
        var items = item,
            len = 1,
            contextItem, i;

        // NOTE: we don't pre-check for validity because:
        //  - maybe only one dimension is valid
        //  - the diagnostics layer will track the setProp call to help find who is trying
        //      (but failing) to set a property
        //  - setProp already checks this anyway

        if (item.isComposite) {
            items = item.elements;
            len = items.length;
            item = items[0];
        } else if (!item.dom && !item.el) { // array by process of elimination
            len = items.length;
            item = items[0];
        }
        // else len = 1 and items = item (to avoid error on "items[++i]")

        for (i = 0; i < len; ) {
            contextItem = this.get(item);
            contextItem.setSize(width, height);

            item = items[++i]; // this accomodation avoids making an array of 1
        }
    }