如何在推理时向Keras中的激活添加噪声？

from keras.layers import Activation
from keras import backend as K
import numpy as np

class NoisyActivation(Activation):
    def __init__(self, activation, noise_stddev, **kwargs):
        super(NoisyActivation, self).__init__(activation, **kwargs)
        self.noise_stddev = noise_stddev

    def call(self, inputs):
        # 生成与输入形状相同的噪声
        noise = K.random_normal(shape=K.shape(inputs), mean=0., stddev=self.noise_stddev)
        # 将噪声添加到输入上
        noisy_inputs = inputs + noise
        # 调用父类的call方法，将添加噪声后的输入传递给激活函数
        return super(NoisyActivation, self).call(noisy_inputs)

from keras.models import Sequential
from keras.layers import Dense

model = Sequential()
model.add(Dense(64, input_dim=100))
model.add(NoisyActivation('relu', noise_stddev=0.1))
model.add(Dense(10))
model.add(Activation('softmax'))