code: def test_label_replace():
      from nni.mutable.utils import label
  
      l = label(["model", "1"])
      assert isinstance(l, label)
      assert isinstance(l, str)
      assert l.replace("/", "__") == "model__1"
  
file_path: nni/test/ut/sdk/mutable/test_label.py
imports: import pytest
  from nni.mutable import label_scope, auto_label
  from nni.mutable.utils import reset_uid
label_desc: Use image node_id 7 for calling a global function with example usage: test_label_replace() without return types