def _do_get_featuregroup_features_list(featuregroup, version,
    featurestore_metadata):
    """
    Gets a list of all names of features in a featuregroup in a featurestore.

    Args:
        :featuregroup: Featuregroup name.
        :version: Version of the featuregroup to use.
        :featurestore_metadata: Metadata of the featurestore.

    Returns:
        A list of names of the features in this featuregroup.
    """
    featuregroup_version = featuregroup + '_' + str(version)
    features = featurestore_metadata.featuregroups[featuregroup_version
        ].features
    return list(map(lambda f: f.name, features))
