class_docstr: Just a simple model, which applies the Laplacian-operation to images to showcase
  the usage of variables, and alternating the inference-graph later.
class_docstr_tok: ["Just","a","simple","model",",","which","applies","the","Laplacian-operation","to","images","to","showcase","the","usage","of","variables",",","and","alternating","the","inference-graph","later","."]
code: def optimizer(self):
      lr = tf.get_variable(
          "learning_rate", initializer=0.0, trainable=False
      )
      return tf.train.AdamOptimizer(lr)
  
imports: import argparse
  import cv2
  from tensorpack import tfv1
  from tensorpack import *
  from tensorpack.tfutils.export import ModelExporter
label_desc: Use image node_id 4 for calling the Model obj's underlying member method code with example usage: obj.optimizer() and returns: tf