docs: public void checkForValue(final double VALUE) {
          boolean wasInSection = contains(checkedValue);
          boolean isInSection  = contains(VALUE);
          if (!wasInSection && isInSection) {
              fireSectionEvent(ENTERED_EVENT);
          } else if (wasInSection && !isInSection) {
              fireSectionEvent(LEFT_EVENT);
          }
          checkedValue = VALUE;
      }