private static String checkNamespaceCollision(final Namespace namespace,
                                                final Namespace other) {
    String p1, p2, u1, u2, reason;

    reason = null;
    p1 = namespace.getPrefix();
    u1 = namespace.getURI();
    p2 = other.getPrefix();
    u2 = other.getURI();
    if (p1.equals(p2) && !u1.equals(u2)) {
      reason = "The namespace prefix \"" + p1 + "\" collides";
    }
    return reason;
  }
private static String checkNamespaceCollision(final Namespace namespace,
                                                final Namespace other)