code: def test_pair_norm(scale_individually):
      x = torch.randn(100, 16)
      batch = torch.zeros(100, dtype=torch.long)
  
      norm = PairNorm(scale_individually=scale_individually)
      assert str(norm) == "PairNorm()"
  
      if is_full_test():
          torch.jit.script(norm)
  
      out1 = norm(x)
      assert out1.size() == (100, 16)
  
      out2 = norm(
          torch.cat([x, x], dim=0), torch.cat([batch, batch + 1], dim=0)
      )
      assert torch.allclose(out1, out2[:100], atol=1e-6)
      assert torch.allclose(out1, out2[100:], atol=1e-6)
  
imports: import pytest
  import torch
  from torch_geometric.nn import PairNorm
  from torch_geometric.testing import is_full_test
label_desc: Use image node_id 1 for calling a global function with example usage: test_pair_norm(scale_individually) without return types