@Test
public void testDiff() {

  Schema rec1 = SchemaBuilder.record("test")
          .fields()
          .nullableLong("testField", 0).endRecord();
  Schema rec2 = SchemaBuilder.record("test")
          .fields()
          .nullableInt("testField", 0).endRecord();
  String diff = SchemaCompatibilityValidator.diff(rec1, rec2);
    System.out.println(SchemaCompatibilityValidator.diff(rec1, rec2));
  Assert.assertThat(diff, Matchers.containsString("int"));
  Assert.assertThat(diff, Matchers.containsString("long"));
}