code: @VisibleForTesting
      protected void isInRange(final FieldValue<?> fieldValue) {
          if (fieldValue instanceof IntegerFieldValue) {
              final int value = ((IntegerFieldValue) fieldValue).getValue();
              if (!constraints.isInRange(value)) {
                  throw new IllegalArgumentException(String.format(OORANGE, value, constraints.getStartRange(), constraints.getEndRange()));
              }
          }
      }
docs: Check if given number is greater or equal to start range and minor or equal to end range.
  
  @param fieldValue - to be validated
  @throws IllegalArgumentException - if not in range