code: def test_optional_blobfile_dependency():
      prog = """
  import tiktoken
  import sys
  assert "blobfile" not in sys.modules
  """
      subprocess.check_call([sys.executable, "-c", prog])
  
imports: import subprocess
  import sys
  import tiktoken
label_desc: Use image node_id 3 for calling a global function with example usage: test_optional_blobfile_dependency() without return types