Retrives all the required resources.

def _get_all(cls, parent_id=None, grandparent_id=None):
        """Retrives all the required resources."""
        client = cls._get_client()
        endpoint = cls._endpoint.format(resource_id="",
                                        parent_id=parent_id or "",
                                        grandparent_id=grandparent_id or "")
        resources = []
        while True:
            response = client.get_resource(endpoint)
            for raw_data in response.get("value", []):
                raw_data["parentResourceID"] = parent_id
                raw_data["grandParentResourceID"] = grandparent_id
                resources.append(cls.from_raw_data(raw_data))
            endpoint = response.get("nextLink")
            if not endpoint:
                break
        return resources