code: def predict(self, obs):
      out = self.fc1(obs)
      out = self.fc2(out)
      out = self.fc3(out)
      return out
  
imports: import numpy
  import paddle.fluid
  import parl
  import unittest
  from copy import deepcopy
  from paddle.fluid import ParamAttr
  from parl import layers
  from parl.utils import get_gpu_count
  from parl.core.fluid.plutils import fetch_value
label_desc: Use image node_id 2 for calling the TestModel4 obj's underlying member method code with example usage: obj.predict(obs) and returns: out