public int hashCode(Object o, Schema s) {
    HashCodeCalculator calculator = new HashCodeCalculator();
    return calculator.hashCode(o, s);
  }
@Test
  void testHashCode() {
    GenericData.get().hashCode(null, Schema.create(Type.NULL));
    GenericData.get().hashCode(null,
        Schema.createUnion(Arrays.asList(Schema.create(Type.BOOLEAN), Schema.create(Type.STRING))));
    List<CharSequence> stuff = new ArrayList<>();
    stuff.add("string");
    Schema schema = recordSchema();
    GenericRecord r = new GenericData.Record(schema);
    r.put(0, stuff);
    GenericData.get().hashCode(r, schema);
  }