function of discriminator not understood

[dhirajpatnaik16297]

in discriminator.py
def discriminate() has self.cnn_out which has not been initialized but it is working i dont know how?
and what exactly is discriminate() doing?
discriminate() is able to compute cnn_out but at last it is returning self.out() which calls the out()
cnn_out is again passed to the fully connected layer but is cnn_out any way related to discriminate() which computed it and how exactly does "self.cnn_out = tf.concat([self.cnn_out, c], axis=1)" in discriminate() work as self.cnn_out has not been declared or intialized?

please help me to understand in detail.