Solved by JuanFMontesinos in post #4 
              
              
                Because it depends on how the forward were coded. I still recommend you to read about *args and **kwargs but let’s illustrate it with an example. 
if you define your forward function like: 
def forward(*inputs):
   # Here inputs is a list.
   x = convolution(inputs[0])
   y = convolution(inputs[1])
…