def curie_to_obo_uri(curie, base=None) -> str:
    """
    :param curie: association.Curie to be expanded into a URI
    :return: the expanded URI for the given CURIE
    """
    if base is None:
        base = "http://purl.obolibrary.org/obo"

    return "{base}/{ns}_{id}".format(base=base, ns=curie.namespace, id=curie.identity)