code: def test_perceiver_cross_attention(self):
      mha = CrossAttention(
          num_q_channels=10, num_kv_channels=5, num_heads=5, dropout=0.2
      )
      q_tensor = torch.rand(2, 10, 10)
      kv_tensor = torch.rand(2, 5, 5)
      out = mha(q_tensor, kv_tensor)  # torch.Size([2, 10, 10])
      self.assertTrue(out.shape == torch.Size([2, 10, 10]))
  
imports: import unittest
  import torch
  from towhee.models.perceiver.cross_attention import CrossAttention
label_desc: Use image node_id 1 for calling the PerceiverCrossAttentionTest obj's underlying member method code with example usage: obj.test_perceiver_cross_attention() without return types