code: public void addConverter(Converter<?, ?> converter) {
  		GenericConverter.ConvertiblePair typeInfo = getRequiredTypeInfo(converter, Converter.class);
  		Assert.notNull(typeInfo, "Unable to the determine sourceType <S> and targetType " +
  				"<T> which your Converter<S, T> converts between; declare these generic types.");
  		addConverter(new ConverterAdapter(converter, typeInfo));
  	}
docs: implementing ConverterRegistry