Compose absolute path for given `tree`.

    Args:
        pub (obj): :class:`.Tree` instance.
        issn (bool, default False): Compose URL using ISSN.

    Returns:
        str: Absolute path of the tree, without server's address and protocol.

def compose_tree_path(tree, issn=False):
    """
    Compose absolute path for given `tree`.

    Args:
        pub (obj): :class:`.Tree` instance.
        issn (bool, default False): Compose URL using ISSN.

    Returns:
        str: Absolute path of the tree, without server's address and protocol.
    """
    if issn:
        return join(
            "/",
            ISSN_DOWNLOAD_KEY,
            basename(tree.issn)
        )

    return join(
        "/",
        PATH_DOWNLOAD_KEY,
        quote_plus(tree.path).replace("%2F", "/"),
    )