import tensorflow as tf

        self.epsilon = epsilon
        self.data_format = data_format
        self.name = name

    def __call__(self,input_var,**kwargs) :
        mean, var = tf.nn.moments(input_var, self.axis, keep_dims=True)
        ret = (input_var - mean) / tf.sqrt(var+self.epsilon)

        if self.gamma is None :
            return ret
