Hello Sagar,

You can only call the methods in new api coding standard those are defined or (Definition) written in  new api coding standard.

Like Base module's methods (Create,write,unlink,copy,name_get etc) this method can be called with new coding standard.

But those method already defined in old coding standard than you have to pass argument while calling it.

So, you have to follow this way.

new_project_template = self.env['project.project'].duplicate_template(self._cr, self._uid, [my_project_template.id], self._context)

But make sure your current method is defined in new coding standard means you are using decorators in your method while calling this method. otherwise you can not define object using self.env

Otherwise you have to use:

new_project_template = self.pool.get('project.project').duplicate_template(cr, uid, [my_project_template.id], context = context) 

While you are calling methods those are written in old standard you have to pass all those arguments.

Hope this will help.

Rgds,

Anil.