eorgia","germany","ghana","gibraltar","greece","greenland","grenada","guadeloupe","guam","guatemala","guernsey","guinea","guinea-bissau","guyana","haiti","heard island and mcdonald islands","honduras","hong kong","hungary","iceland","india","indonesia","iran","iraq","ireland","isle of man","israel","italy","jamaica","japan","jersey","jordan","kazakhstan","kenya","kiribati","north korea","south korea","kuwait","kyrgyzstan","laos","latvia","lebanon","lesotho","liberia","libya","liechtenstein","lit...

   *     GraphBuilder.undirected()
   *         .<Country>immutable()
   *         .putEdge(FRANCE, GERMANY)
   *         .putEdge(FRANCE, BELGIUM)
   *         .putEdge(GERMANY, BELGIUM)
   *         .addNode(ICELAND)
   *         .build();
   * }</pre>
   *
   * <p>Builder instances can be reused; it is safe to call {@link #build} multiple times to build