void addIDConstraintDecl(IdentityConstraint decl) {
        final String namespace = decl.getNamespace();
        final String declKey = (namespace == null || namespace.length() == 0)
            ? "," + decl.getIdentityConstraintName() : namespace + "," + decl.getIdentityConstraintName();

        if (fGlobalIDConstraintDecls.get(declKey) == null) {
            fGlobalIDConstraintDecls.put(declKey, decl);
        }
    }