def aug_remove(current, extra):
    """Remove extra from current. Not in formal
       specifications. Allowed to fail silently."""
    have_list = isinstance(current, list)
    if have_list:
        if extra in current:
            current.remove(extra)
            return current
        else:
            print('Removal Warning: %s not in %s' % (repr(extra), repr(
                current)))
            return current
    else:
        raise ValueError('Cannot remove %s from %s' % (repr(extra), repr(
            current)))
