code: def encoder(self, imgs):
      with argscope(
          Conv2D, activation=tf.nn.elu, kernel_size=3, strides=1
      ):
          l = (
              LinearWrap(imgs)
              .Conv2D("conv1.1", NF)
              .Conv2D("conv1.2", NF)
              .Conv2D("conv1.3", NF * 2)
              .AvgPooling("pool1", 2)
              # 32
              .Conv2D("conv2.1", NF * 2)
              .Conv2D("conv2.2", NF * 3)
              .AvgPooling("pool2", 2)
              # 16
              .Conv2D("conv3.1", NF * 3)
              .Conv2D("conv3.2", NF * 4)
              .AvgPooling("pool3", 2)
              # 8
              .Conv2D("conv4.1", NF * 4)
              .Conv2D("conv4.2", NF * 4)
              .FullyConnected("fc", NH)()
          )
      return l
  
file_path: tensorpack/examples/GAN/BEGAN.py
imports: import tensorflow
  from tensorpack import *
  from tensorpack.tfutils.scope_utils import auto_reuse_variable_scope
  from tensorpack.tfutils.summary import add_moving_summary
  from tensorpack.utils.gpu import get_num_gpu
  import DCGAN
  from GAN import GANModelDesc, GANTrainer
label_desc: Use image node_id 3 for calling the Model obj's underlying member method code with example usage: obj.encoder(imgs) and returns: l