@Inject(optional = true) void injectBSONDecodingTransformers( @Named(DECODING_NAME) final Map<Class<?>, Transformer> decodingTransformers) { Preconditions.checkNotNull(decodingTransformers, "transformers can not be null!"); for (Map.Entry<Class<?>, Transformer> entry : decodingTransformers.entrySet()) { BSON.addDecodingHook(entry.getKey(), entry.getValue()); } }