code: public void setTrackStart(final double TRACK_START) {
          // check values
          if (Double.compare(TRACK_START, trackStop) == 0) {
              throw new IllegalArgumentException("Track start value cannot equal track stop value");
          }
          trackStart = TRACK_START;
          validate();
          fireStateChanged();
      }
docs: Sets the track start value of the gauge to the given value
  @param TRACK_START