code: static void checkClosedOpen(final Range<Long> range) {
          checkNotNull(range);
          checkArgument(BoundType.CLOSED == range.lowerBoundType(), "range must be [closed, open), lower bound type was open");
          checkArgument(BoundType.OPEN == range.upperBoundType(), "range must be [closed, open), upper bound type was closed");
      }
docs: Confirm that the specified range is [closed, open).
  
  @param range range to check, must not be null