merge function occuring error while executing the code

I have the javascript file which not validating the below ember js code:

helpers = this.merge(helpers, Ember.Handlebars.helpers); data = data || {};
var buffer = '', stack1, escapeExpression=this.escapeExpression, self=this;

While I'm executing the above code, I'm getting this.merge is not a function. (Note: I'm upgrading ember from 1.4.0 to 1.12.2 and I'm using Handlebars 2.0.0). Please provide me the suggestion