@Test
public void testMultipleSerializersInstalled() throws Exception {

  // TODO: The generic component of Comparable causes validation to miss certain error
  // cases like this.
  @SuppressWarnings("rawtypes")
  final class ComparableSerializer extends DefaultValueSerializer<Comparable<String>, Integer> {}
  final class CharSequenceSerializer extends DefaultValueSerializer<CharSequence, Long> {}
  config.getSerializationConfig().addSerializationConfig(ComparableSerializer.class);
  config.getSerializationConfig().addSerializationConfig(CharSequenceSerializer.class);
  try {
    validator.validate(config);
    fail("Expected MultipleTransformersException.");
  } catch (MultipleTransformersException expected) {
  }
}