code: def test_container_cannot_change_type(self):
      x = nnx.Variable(1)
  
      with pytest.raises(
          ValueError, match="is not compatible with return type"
      ):
          x = nnx.Param(x)
  
      x = nnx.Param(2)
  
      with pytest.raises(
          ValueError, match="is not compatible with return type"
      ):
          x = nnx.Variable(x)
  
file_path: flax/flax/experimental/nnx/tests/test_containers.py
imports: import pytest
  from flax.experimental import nnx
label_desc: Use image node_id 4 for calling the TestContainers obj's underlying member method code with example usage: obj.test_container_cannot_change_type() without return types