@Override
    public TypeSerializerSchemaCompatibility<T> resolveSchemaCompatibility(
            TypeSerializerSnapshot<T> oldSerializerSnapshot) {
        if (!(oldSerializerSnapshot instanceof AvroSerializerSnapshot)) {
            return TypeSerializerSchemaCompatibility.incompatible();
        }
        AvroSerializerSnapshot<?> oldAvroSerializerSnapshot =
                (AvroSerializerSnapshot<?>) oldSerializerSnapshot;
        return resolveSchemaCompatibility(oldAvroSerializerSnapshot.schema, schema);
    }
@Test
    void addingAnOptionalFieldsIsCompatibleAsIs() {
        assertThat(
                        AvroSerializerSnapshot.resolveSchemaCompatibility(
                                FIRST_NAME, FIRST_REQUIRED_LAST_OPTIONAL))
                .is(isCompatibleAfterMigration());
    }