def get_all_distribution_names(url=None):
    """
    Return all distribution names known by an index.
    :param url: The URL of the index.
    :return: A list of all known distribution names.
    """
    if url is None:
        url = DEFAULT_INDEX
    client = ServerProxy(url, timeout=3.0)
    try:
        return client.list_packages()
    finally:
        client('close')()

    Return all distribution names known by an index.
    :param url: The URL of the index.
    :return: A list of all known distribution names.
    
product/gradle-plugin/src/main/python/pip/_vendor/distlib/locators.py