Actually, this section of code shouldn't have env_var or files defined at all, that's part of what I was trying to strip out. The default values are built into the convenience function. But this would be a good opportunity to make that function signature better anyways.

    def configure_identity_cache(cache, filenames=['~/.ejtp/idents.json', '~/.ejtp/console/idents.json']):
        for filename in test_filenames(filenames, 'EJTP_IDENTITY_CACHE_PATH'):
            cache.load_from(filename)