### Question:
PositiveIntegerAdapter extends IntegerAdapter { @Override public Integer unmarshal(String value){ Integer result = super.unmarshal(value); if(!isValid(result)){ throw new IllegalArgumentException(value); } return result; }  @Override Integer unmarshal(String value); static boolean isValid(Integer value);  }### Answer:
@Test public void unmarshal(){ IntegerAdapter adapter = new PositiveIntegerAdapter(); try { adapter.unmarshal("-1"); fail(); } catch(IllegalArgumentException iae){ } try { adapter.unmarshal("0"); fail(); } catch(IllegalArgumentException iae){ } assertEquals((Integer)1, adapter.unmarshal("1")); }