'Add an included and possibly renamed non-wildcard Namespace.'

def _add_plain_namespace(self, namespace):

    src_name = namespace.source_name
    target_name = namespace.dest_name
    src_names = self._reverse_plain.setdefault(target_name, set())
    src_names.add(src_name)
    if (len(src_names) > 1):
        existing_src = (src_names - set([src_name])).pop()
        raise errors.InvalidConfiguration(("Multiple    namespaces    cannot    be    combined    into    one    target    namespace.    Trying    to    map    '%s'    to    '%s'    but    there    already    exists    a    mapping    from    '%s'    to    '%s'" % (src_name, target_name, existing_src, target_name)))
    self._plain[src_name] = namespace
    (src_db, _) = src_name.split('.', 1)
    (target_db, _) = target_name.split('.', 1)
    self._plain_db.setdefault(src_db, set()).add(target_db)
