Review

class SortedDependencies {
  /**
   * Returns the first circular dependency found. Expressed as a list of
   * items in reverse dependency order (the second element depends on the
   * first, etc.).
   */
  private List<INPUT> findCycle(
      List<INPUT> subGraph, Multimap<INPUT, INPUT> deps) {
    return findCycle(subGraph.get(0), Sets.<INPUT>newHashSet(subGraph),
        deps, Sets.<INPUT>newHashSet());
  }

}