public static GenericData get() {
    return INSTANCE;
  }
@Test
  void arraySet() {
    Schema schema = Schema.createArray(Schema.create(Schema.Type.INT));
    GenericArray<Integer> array = new GenericData.Array<>(10, schema);
    array.clear();
    for (int i = 0; i < 10; ++i)
      array.add(i);
    assertEquals(10, array.size());
    assertEquals(Integer.valueOf(0), array.get(0));
    assertEquals(Integer.valueOf(5), array.get(5));

    assertEquals(Integer.valueOf(5), array.set(5, 55));
    assertEquals(10, array.size());
    assertEquals(Integer.valueOf(55), array.get(5));
  }