code: def forward(self, obs_n, act_n):
      inputs = torch.cat(obs_n + act_n, dim=1)
      hid1 = F.relu(self.fc1(inputs))
      hid2 = F.relu(self.fc2(hid1))
      Q = self.fc3(hid2)
      Q = torch.squeeze(Q, dim=1)
      return Q
  
file_path: PARL/benchmark/torch/maddpg/simple_model.py
imports: import parl
  import torch
  import torch.nn
  import torch.nn.functional
label_desc: Use image node_id 2 for calling the CriticModel obj's underlying member method code with example usage: obj.forward(obs_n, act_n) and returns: Q