code: def test_register_unknown_hooks(pm: PluginManager) -> None:
      class Plugin1:
          @hookimpl
          def he_method1(self, arg):
              return arg + 1
  
      pname = pm.register(Plugin1())
      assert pname is not None
  
      class Hooks:
          @hookspec
          def he_method1(self, arg):
              pass
  
      pm.add_hookspecs(Hooks)
      # assert not pm._unverified_hooks
      assert pm.hook.he_method1(arg=1) == [2]
      hookcallers = pm.get_hookcallers(pm.get_plugin(pname))
      assert hookcallers is not None
      assert len(hookcallers) == 1
  
imports: import sys
  from typing import Any
  from typing import List
  import pytest
  from pluggy import HookCallError
  from pluggy import HookimplMarker
  from pluggy import HookspecMarker
  from pluggy import PluginManager
  from pluggy import PluginValidationError
label_desc: Use image node_id 12 for calling a global function with example usage: test_register_unknown_hooks(pm) and returns: unknown