lib/Ext/dom/Element.static.js
function(size, units) {
        // Size set to a value which means "auto"
        if (size === "" || size == "auto" || size === undefined || size === null) {
            return size || '';
        }

        // Otherwise, warn if it's not a valid CSS measurement
        if (Ext.isNumber(size) || this.numberRe.test(size)) {
            return size + (units || this.defaultUnit || 'px');
        }
        else if (!this.unitRe.test(size)) {
            //<debug>
            Ext.Logger.warn("Warning, size detected (" + size + ") not a valid property value on Element.addUnits.");
            //</debug>
            return size || '';
        }

        return size;
    }
function(size, units) {
        // Size set to a value which means "auto"
        if (size === "" || size == "auto" || size === undefined || size === null) {
            return size || '';
        }

        // Otherwise, warn if it's not a valid CSS measurement
        if (Ext.isNumber(size) || this.numberRe.test(size)) {
            return size + (units || this.defaultUnit || 'px');
        }
        else if (!this.unitRe.test(size)) {
            //<debug>
            Ext.Logger.warn("Warning, size detected (" + size + ") not a valid property value on Element.addUnits.");
            //</debug>
            return size || '';
        }

        return size;
    }
Test if size has a unit, otherwise appends the passed unit string, or the default for this Element.
@param {Object} size The size to set.
@param {String} units The units to append to a numeric size value.
@return {String}
@private
@static