client = BacklogClient("your_space_name", "your_api_key")
        client.project_activities("YOUR_PROJECT")
        client.project_activities("YOUR_PROJECT", {"activityTypeId[]": [1, 2],})

def project_activities(self, project_id_or_key, extra_query_params={}):
        """
        client = BacklogClient("your_space_name", "your_api_key")
        client.project_activities("YOUR_PROJECT")
        client.project_activities("YOUR_PROJECT", {"activityTypeId[]": [1, 2],})
        """
        return self.do("get", "projects/{project_id_or_key}/activities",
                       url_params={"project_id_or_key": project_id_or_key},
                       query_params=extra_query_params,
                       )