Remove redundant check for parameters.

lib/notification.js

 'use strict';
 
+// TODO Deprecate
 var ALLOWED_FIELDS = ['contents', 'included_segments', 'excluded_segments', 'filters', 'include_player_ids',
 	'app_id', 'app_ids', 'headings', 'subtitle', 'template_id', 'content_available', 'mutable_content',
 	'data', 'url', 'ios_attachments', 'big_picture', 'adm_big_picture', 'chrome_big_picture', 'buttons',
@@ -46,11 +47,9 @@ var Notification = function (initialBody) {
  * @param value
  */
 Notification.prototype.setParameter = function (name, value) {
+  // TODO Deprecate
 	if (name && name[0] === '!') {
 		name = name.substring(1);
-	} else if (ALLOWED_FIELDS.indexOf(name) === -1) {
-		throw '"' + name +  '" is not present in documentation. You should add a ' +
-		'exclamation mark to the begging of the name, if you want to set it : !' + name;
 	}
 	this.postBody[name] = value;
 };