code: function(data) {
  			data = data || {};
  			var paramNames = Object.keys(data);
  			var buf = [];
  			for (var i=0; i < paramNames.length; i++) {
  				var param = paramNames[i], value = data[param];
  				buf.push(x_www_form_urlencode(param) + '=' + x_www_form_urlencode(value)); //$NON-NLS-0$
  			}
  			return buf.join('&'); //$NON-NLS-0$
  		}
docs: Encodes an object of form fields and values into an <code>application/x-www-form-urlencoded</code> string.
  @static
  @param {Object} data The form data to encode.
  @returns {String} The <code>x-www-form-urlencoded</code> string.