def adata():
    adata = ad.AnnData(np.zeros((100, 100)))
    adata.obsm["o"] = np.zeros((100, 50))
    adata.varm["o"] = np.zeros((100, 50))
    return adata
def isexact(self):
        """Matcher will match exactly the list of files in .files() --
        optimization might be possible."""
        return False