code: public static <T> ComparisonChain compare(T left, T right, Comparator<T> comparator) {
          return new ComparisonChain().compare(left, right, comparator);
      }
docs: Compares two objects using a comparator, <i>if</i> the result of this
  comparison chain has not already been determined.
  
  @param left
  @param right
  @return {@code ComparisonChain}