code: def setUp(self):
      self.s = 64
      feat_sizes = [self.s // 2**i for i in range(4)]
      self.in_channels = [8, 16, 32, 64]
      self.out_channels = 4
      self.feature = [
          torch.rand(
              1, self.in_channels[i], feat_sizes[i], feat_sizes[i]
          )
          for i in range(len(self.in_channels))
      ]
  
imports: import unittest
  import torch
  from mmocr.models.textdet.necks import FPN_UNet
label_desc: Use image node_id 1 for calling the TestFPNUnet obj's underlying member method code with example usage: obj.setUp() without return types