code: public void registerType(Class<?> type) {
  		if (type == null) {
  			throw new NullPointerException("Cannot register null type class.");
  		}
  
  		TypeInformation<?> typeInfo = TypeExtractor.createTypeInfo(type);
  
  		if (typeInfo instanceof PojoTypeInfo) {
  			config.registerPojoType(type);
  		} else {
  			config.registerKryoType(type);
  		}
  	}
docs: Registers the given type with the serialization stack. If the type is
  eventually serialized as a POJO, then the type is registered with the
  POJO serializer. If the type ends up being serialized with Kryo, then it
  will be registered at Kryo to make sure that only tags are written.
  
  @param type
  The class of the type to register.