public void addDefault(Class<?> srcClass, Class<?> destClass, ClassMap classMap) {
        classMappings.put(keyFactory.createKey(srcClass, destClass), classMap);
    }
Internal class that determines the appropriate class mapping to be used for
the source and destination object being mapped. Only intended for internal
use.
core/src/main/java/com/github/dozermapper/core/classmap/ClassMappings.java