max_size argument that controls the image_pool

[mark-joe]

Recently start using this tensorflow implementation of CycleGAN. Does anybody knows the function of the imagepool (that is controlled by the max_size argument). It is kind of a buffer to store fake_A's and fake_B's to be fed to the discriminator. And if the buffer is full it randomly takes an old one, or a new one. But the old ones never get replaced during training, which seems odd. Any clues on this anyone?