code: def test_user_agent_with_library_name_no_version(self) -> None:
      self.assertTrue(
          self._get_user_agent(library_name="foo").startswith(
              "foo/None;"
          )
      )
  
imports: import unittest
  from unittest.mock import Mock, patch
  from huggingface_hub.utils import get_hf_hub_version, get_python_version
  from huggingface_hub.utils._headers import _deduplicate_user_agent, _http_user_agent, build_hf_headers
  from .testing_utils import handle_injection_in_test
label_desc: Use image node_id 5 for calling the TestUserAgentHeadersUtil obj's underlying member method code with example usage: obj.test_user_agent_with_library_name_no_version() without return types