code: def setUp(self):
      self.batch_size = 2
      self.num_actions = 3
      self.logits = torch.rand(size=(self.batch_size, self.num_actions))
      self.dist = CategoricalDistribution(self.logits)
  
imports: import random
  import copy
  import numpy
  import torch
  import unittest
  from parl.core.torch.policy_distribution import DiagGaussianDistribution, CategoricalDistribution, SoftCategoricalDistribution, SoftMultiCategoricalDistribution
label_desc: Use image node_id 1 for calling the CategoricalDistributionTest obj's underlying member method code with example usage: obj.setUp() without return types