private void addImportList(SchemaGrammar sg, Vector importedGrammars, Vector namespaceList) {
        final int size = namespaceList.size();
        SchemaGrammar isg;

        for (int i=0; i<size; i++) {
            isg = fGrammarBucket.getGrammar((String)namespaceList.elementAt(i));
            if (isg != null) {
                importedGrammars.add(isg);
            }
            else {
                //REVIST: report an error message
            }
        }
    }