I have to try to override one method in my module. The base method is ​split_context it is in the api.py. I have tried with the override from odoo import api and then override all the method. 

            def split_context(method, args, kwargs):
                 pos = len(getargspec(method).args) - 1
                    if pos < len(args):
                             return args[pos], args[:pos], kwargs
                    else:
                      return kwargs.pop('context', None), args, kwargs          

but the method is not called in my custom module