code: private static TransitionType getTransitionType(String groupIn, Collection<String> neighborGroups)
      {
          final boolean[] bits = new boolean[TransitionType.BITS];
          int i = 0;
          for (final String neighborGroup : neighborGroups)
          {
              bits[i] = !groupIn.equals(neighborGroup);
              i++;
          }
          return TransitionType.from(bits);
      }
docs: Get the transition type from one group to another.
  
  @param groupIn The group in.
  @param neighborGroups The neighbor groups.
  @return The tile transition.