code: private static void checkPreconditions(final int min, final int max) {
          if( min > max ) {
              throw new IllegalArgumentException(String.format("max (%d) should not be < min (%d)", max, min));
          }
          
          if( min < 0 ) {
              throw new IllegalArgumentException(String.format("min length (%d) should not be < 0", min));
          }
      }
docs: Checks the preconditions for creating a new {@link LengthBetween} processor.
  
  @param min
  the minimum String length
  @param max
  the maximum String length
  @throws IllegalArgumentException
  {@literal if max < min, or min is < 0}