def query(self, keys, offset=0):
        """Queries the cache.

        Parameters
        ----------
        keys : Tensor
            The keys to query the cache with.
        offset : int
            The offset to be added to the keys. Default is 0.

        Returns
        -------
        tuple(Tensor, Tensor, Tensor, Tensor)
            A tuple containing
            (values, missing_indices, missing_keys, missing_offsets) where
            values[missing_indices] corresponds to cache misses that should be
            filled by quering another source with missing_keys. If keys is
            pinned, then the returned values tensor is pinned as well. The
            missing_offsets tensor has the partition offsets of missing_keys.
        """
        self.total_queries += keys.shape[0]
        (
            positions,
            index,
            missing_keys,
            found_pointers,
            found_offsets,
            missing_offsets,
        ) = self._policy.query(keys, offset)
        values = self._cache.query(positions, index, keys.shape[0])
        self._policy.reading_completed(found_pointers, found_offsets)
        self.total_miss += missing_keys.shape[0]
        missing_index = index[positions.size(0) :]
        return values, missing_index, missing_keys, missing_offsets
Queries the cache.

        Parameters
        ----------
        keys : Tensor
            The keys to query the cache with.
        offset : int
            The offset to be added to the keys. Default is 0.

        Returns
        -------
        tuple(Tensor, Tensor, Tensor, Tensor)
            A tuple containing
            (values, missing_indices, missing_keys, missing_offsets) where
            values[missing_indices] corresponds to cache misses that should be
            filled by quering another source with missing_keys. If keys is
            pinned, then the returned values tensor is pinned as well. The
            missing_offsets tensor has the partition offsets of missing_keys.
        
python/dgl/graphbolt/impl/cpu_feature_cache.py