public Class getCustomConverter(Class<?> srcClass, Class<?> destClass, Cache converterTypeCache) {
        if (converters.isEmpty()) {
            return null;
        }

        // Check cache first
        final Object cacheKey = CacheKeyFactory.createKey(destClass, srcClass);
        if (converterTypeCache.containsKey(cacheKey)) { // even null
            return (Class)converterTypeCache.get(cacheKey);
        }

        // Let's see if the incoming class is a primitive:
        final Class src = ClassUtils.primitiveToWrapper(srcClass);
        final Class dest = ClassUtils.primitiveToWrapper(destClass);

        Class appropriateConverter = findConverter(src, dest);
        converterTypeCache.put(cacheKey, appropriateConverter);

        return appropriateConverter;
    }
Internal class for holding custom converter definitions. Only intended for internal use.
core/src/main/java/com/github/dozermapper/core/converters/CustomConverterContainer.java