code: def test_mixed_conv2d(self):
      in_channels = 32
      out_channels = 64
      kernel_size = 3
      stride = 1
      padding = "same"
      module = MixedConv2d(
          in_channels, out_channels, kernel_size, stride, padding
      )
      x = torch.FloatTensor(1, 32, 224, 224)
      output = module(x)
      gt_output_shape = torch.Size((1, 64, 224, 224))
      self.assertTrue(output.shape == gt_output_shape)
  
imports: import unittest
  import torch
  from towhee.models.layers.mixed_conv2d import MixedConv2d
label_desc: Use image node_id 1 for calling the MxiedConv2dTest obj's underlying member method code with example usage: obj.test_mixed_conv2d() without return types