private GenericConverter getRegisteredConverter(Class<?> sourceType, Class<?> targetType,
														Class<?> sourceCandidate, Class<?> targetCandidate) {
			ConvertersForPair convertersForPair = converters.get(new ConvertiblePair(sourceCandidate, targetCandidate));
			return convertersForPair == null ? null : convertersForPair.getConverter(sourceType, targetType);
		}