'init param might contain nested lists, typically from group flags.
This code organises lst and remves dupes'

def _as_one_list(self, items):

    if ((type(items) != type([])) and (type(items) != type(()))):
        return [items]
    r = []
    for l in items:
        if (type(l) == type([])):
            lst2 = self._as_one_list(l)
            for l2 in lst2:
                self._append_unique_str(r, l2)
        elif (l == None):
            continue
        else:
            self._append_unique_str(r, l)
    return r
