def test_set_var(adata, subset_func):
    init_hash = joblib.hash(adata)

    subset = adata[:, subset_func(adata.var_names)]

    new_var = pd.DataFrame(
        dict(a=np.ones(subset.n_vars), b=np.ones(subset.n_vars)),
        index=subset.var_names,
    )

    assert subset.is_view
    subset.var = new_var
    assert not subset.is_view
    assert np.all(subset.var == new_var)

    assert joblib.hash(adata) == init_hash
def _get_or_create_cached_value(self, key, getter, ttl=None):
        # happy path
        try:
            expiry, value = self._cache[key]
        except KeyError:
            pass
        else:
            if expiry is None or time.time() < expiry:
                logger.debug("Key %s from cache", key)
                return value
            logger.debug("Cache for key %s has expired", key)

        # get value
        value = getter()
        if ttl:
            expiry = time.time() + ttl
        else:
            expiry = None
        self._cache[key] = (expiry, value)
        logger.debug("Set cache for key %s", key)

        return value