code: public SerDeserializer findDeserializer(Class<?> type) {
          SerDeserializer deser = deserializers.get(type);
          if (deser != null) {
              return deser;
          }
          for (SerDeserializerProvider provider : providers) {
              deser = provider.findDeserializer(type);
              if (deser != null) {
                  return deser;
              }
          }
          return defaultDeserializer;
      }
docs: Finds the deserializer for the specified type.
  <p>
  The {@code DefaultDeserializer} is used if one has not been registered.
  
  @param type  the type, not null
  @return the deserializer, not null