code: @Override
      public int compareTo(ICECandidate arg) {
          if (getPreference() < arg.getPreference()) {
              return -1;
          } else if (getPreference() > arg.getPreference()) {
              return 1;
          }
          return 0;
      }
docs: Compare the to other Transport candidate.
  
  @param arg another Transport candidate
  @return a negative integer, zero, or a positive integer as this
  object is less than, equal to, or greater than the specified
  object