class_docstr: Simple feed forward policy network.
      
class_docstr_tok: ["Simple","feed","forward","policy","network","."]
docstr: forward pass. 
docstr_tok: ["forward","pass","."]
code: def forward(self, x):
      """forward pass."""
      return self.net(x)
  
file_path: maze/tutorials/examples/cartpole_custom_net.py
imports: from torch import nn
  from maze.perception.blocks.feed_forward.dense import DenseBlock
  from maze.perception.blocks.inference import InferenceBlock
  from maze.perception.blocks.output.linear import LinearOutputBlock
  from maze.perception.weight_init import make_module_init_normc
label_desc: Use image node_id 2 for calling the PolicyNet obj's underlying member method code with example usage: obj.forward(x) and returns: self