validateIncludedElements not public method

lib/model.js

@@ -1764,7 +1764,6 @@ module.exports = (function() {
       options.hasIncludeRequired = options.hasIncludeRequired || include.hasIncludeRequired || !!include.required;
     }
   };
-  Model.$validateIncludedElements = validateIncludedElements;
 
   var validateIncludedElement = function(include, tableNames) {
     if (!include.hasOwnProperty('model') && !include.hasOwnProperty('association')) {