def get_known_transports():
    """Return a dictionary of all known transport mechanisms."""
    if not hasattr(get_known_transports, "cache"):
        setattr(
            get_known_transports,
            "cache",
            {
                e.name: e.load()
                for e in pkg_resources.iter_entry_points("workflows.transport")
            },
        )
    return get_known_transports.cache.copy()