in Lasagne, the code like this:
l_in_imgdim = nn.layers.InputLayer(
        shape=(batch_size, 2),
        name='imgdim'
    )

layers = []
l_conv = Conv2DLayer(layers[-1],
                         num_filters=32, filter_size=(7, 7), stride=(2, 2),
                         border_mode='same',
                         W=nn.init.Orthogonal(1.0), b=nn.init.Constant(0.1),
                         untie_biases=True)
layers.append(l_conv)
# after adding some common layers here...and the last one of these is FC-layer.
l_first_repr = layers[-1]
l_coarse_repr = nn.layers.concat([l_first_repr,    l_in_imgdim])
layers.append(l_coarse_repr)

My goal is to implement the networks based on Lasagne by Pytorch.