def runtimeclasses():
    """Returns a set of all RUNTIME classes.
    """
    rtset = set()
    for cn in immom.getclassnames():
        (c, a) = immom.getclass(cn)
        if c == 'RUNTIME':
            rtset.add(cn)
    return rtset
def configrtclasses():
    """Returns a set of all CONFIG classes with RUNTIME attributes.
    Use; configclasses() - configrtclasses()
    to get a set of all pure config classes.
    """
    rtset = set()
    for cn in configclasses():
        (c, a) = immom.getclass(cn)
        for (n, t, f, d) in a:
            if 'RUNTIME' in f:
                rtset.add(cn)
    return rtset