code: def test_prefix_hookimpl(include_hookspec):
      with pytest.deprecated_call():
          pm = PluginManager(hookspec.project_name, "hello_")
  
      if include_hookspec:
  
          class HookSpec(object):
              @hookspec
              def hello_myhook(self, arg1):
                  """add to arg1"""
  
          pm.add_hookspecs(HookSpec)
  
      class Plugin(object):
          def hello_myhook(self, arg1):
              return arg1 + 1
  
      with pytest.deprecated_call():
          pm.register(Plugin())
          pm.register(Plugin())
      results = pm.hook.hello_myhook(arg1=17)
      assert results == [18, 18]
  
imports: import pytest
  import types
  from pluggy import PluginManager, PluginValidationError, HookCallError, HookimplMarker, HookspecMarker
  from pluggy.manager import importlib_metadata
label_desc: Use image node_id 25 for calling a global function with example usage: test_prefix_hookimpl(include_hookspec) and returns: unknown