def test_negative_scalar_index(adata, index: int, obs: bool):
    pos_index = index + (adata.n_obs if obs else adata.n_vars)

    if obs:
        adata_pos_subset = adata[pos_index]
        adata_neg_subset = adata[index]
    else:
        adata_pos_subset = adata[:, pos_index]
        adata_neg_subset = adata[:, index]

    np.testing.assert_array_equal(
        adata_pos_subset.obs_names, adata_neg_subset.obs_names
    )
    np.testing.assert_array_equal(
        adata_pos_subset.var_names, adata_neg_subset.var_names
    )
def addOperators(self, num, target):
        """
        Adapted from https://leetcode.com/discuss/58614/java-standard-backtrace-ac-solutoin-short-and-clear

        Algorithm:
        1. DFS
        2. Special handling for multiplication
        3. Detect invalid number with leading 0's
        :type num: str
        :type target: int
        :rtype: List[str]
        """
        ret = []
        self.dfs(num, target, 0, "", 0, 0, ret)
        return ret