You are coding in a method which has API styling... hence your self will be a environment browse variable..

Hence when you are trying to call the method of same object, you need not to pass all the argument,,

just write it like this: self.mymethod()

Note:

calling of method is depends on the convention of the object declaration

Say user object and partner object:

def sample_method(self):
    parter_obj = self.pool.get('res.partner')
    user_env = self.env['res.users']       

    partner_obj.calling_method(cr, uid, new_partner_id)  [Old style since object is declared as Pool]
    new_user_browse.calling_method()  [API style since object is declared as Environment]

I have written both styling in API style method, hope you got the difference