code: def forward(self, obs_1, obs_2):
      out = self.fc1(obs_1)
      out = self.fc2(paddle.concat([out, obs_2], 1))
      out = self.fc3(out)
      return out
  
imports: import numpy
  import unittest
  import paddle
  import paddle.nn
  import parl
  import os
label_desc: Use image node_id 2 for calling the DoubleInputTestModel obj's underlying member method code with example usage: obj.forward(obs_1, obs_2) and returns: out