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: return list of distinfo/plugin tuples for all setuptools registered
  plugins. 
docstr_tok: ["return","list","of","distinfo\/plugin","tuples","for","all","setuptools","registered","plugins","."]
code: def list_plugin_distinfo(self):
      """return list of distinfo/plugin tuples for all setuptools registered
      plugins."""
      return list(self._plugin_distinfo)
  
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 19 for calling the PluginManager obj's underlying member method code with example usage: obj.list_plugin_distinfo() and returns: list