api/1.0/plan/{projectKey}-{buildKey}/branch

def plan_branches(self, plan_key, expand=None, favourite=False, clover_enabled=False, max_results=25):
        """api/1.0/plan/{projectKey}-{buildKey}/branch"""
        resource = 'plan/{}/branch'.format(plan_key)
        return self.base_list_call(resource, expand, favourite, clover_enabled, max_results,
                                   elements_key='branches', element_key='branch')