code: function (keyOrList) {
  				var keys = toArray(keyOrList);
  				for (var i = keys.length; --i >= 0;) {
  					if (!hasOwn.call(props, keys[i])) {
  						return false;
  					}
  				}
  				return true;
  			}
docs: Returns true iff all of the specified keys exist (regardless of value).