def call(self, x, mask=None):
        boolean_mask = K.any(K.not_equal(x, self.mask_value),
                             axis=-1, keepdims=True)
        return x - K.cast(boolean_mask, K.floatx())
dataset/ETHPy150Open fchollet/keras/keras/layers/core.py/Masking.call/operator `*` -> `-`