class_docstr: Core :py:class:`.PluginManager` class which manages registration
  of plugin objects and 1:N hook calling.
  
  You can register new hooks by calling :py:meth:`add_hookspecs(module_or_class)
  <.PluginManager.add_hookspecs>`.
  You can register plugin objects (which contain hooks) by calling
  :py:meth:`register(plugin) <.PluginManager.register>`.  The :py:class:`.PluginManager`
  is initialized with a prefix that is searched for in the names of the dict
  of registered plugin objects.
  
  For debugging purposes you can call :py:meth:`.PluginManager.enable_tracing`
  which will subsequently send debug information to the trace helper.
docstr: Verify that all hooks which have not been verified against
  a hook specification are optional, otherwise raise :py:class:`.PluginValidationError`.
docstr_tok: ["Verify","that","all","hooks","which","have","not","been","verified","against","a","hook","specification","are","optional",",","otherwise","raise",":","py",":","class",":","`",".PluginValidationError","`","."]
code: def check_pending(self):
      """Verify that all hooks which have not been verified against
      a hook specification are optional, otherwise raise :py:class:`.PluginValidationError`.
      """
      for name in self.hook.__dict__:
          if name[0] != "_":
              hook = getattr(self.hook, name)
              if not hook.has_spec():
                  for hookimpl in hook.get_hookimpls():
                      if not hookimpl.optionalhook:
                          raise PluginValidationError(
                              hookimpl.plugin,
                              "unknown hook %r in plugin %r"
                              % (name, hookimpl.plugin),
                          )
  
imports: import inspect
  import sys
  from .None import _tracing
  from .callers import _Result
  from .hooks import HookImpl, _HookRelay, _HookCaller, normalize_hookimpl_opts
  import warnings
label_desc: Use image node_id 17 for calling the PluginManager obj's underlying member method code with example usage: obj.check_pending() without return types