@SuppressWarnings("unchecked")
    @Override
    public OUT extract(Object in) {
        return (OUT) Array.get(in, fieldId);
    }
@Test
    void testIntegerArray() {
        for (int i = 0; i < this.testIntegerArray.length; i++) {
            assertThat(new FieldFromArray<Integer>(i).extract(testIntegerArray))
                    .isEqualTo(testIntegerArray[i]);
        }
    }