def _populate_cache(self):
        """
        Populates the result cache with ``ITER_CHUNK_SIZE`` more entries
        (until the cursor is exhausted).
        """
        if self._result_cache is None:
            self._result_cache = []
        if self._has_more:
            try:
                for i in xrange(ITER_CHUNK_SIZE):
                    self._result_cache.append(self.next())
            except __HOLE__:
                self._has_more = False
dataset/ETHPy150Open MongoEngine/mongoengine/mongoengine/queryset/queryset.py/QuerySet._populate_cache