class_docstr: Metaclass for defining Abstract Base Classes (ABCs).
  
  Use this metaclass to create an ABC.  An ABC can be subclassed
  directly, and then acts as a mix-in class.  You can also register
  unrelated concrete classes (even built-in classes) and unrelated
  ABCs as 'virtual subclasses' -- these and their descendants will
  be considered subclasses of the registering ABC by the built-in
  issubclass() function, but the registering ABC won't show up in
  their MRO (Method Resolution Order) nor will method
  implementations defined by the registering ABC be callable (not
  even via super()).
class_docstr_tok: ["Metaclass","for","defining","Abstract","Base","Classes","(","ABCs",")",".","Use","this","metaclass","to","create","an","ABC",".","An","ABC","can","be","subclassed","directly",",","and","then","acts","as","a","mix-in","class",".","You","can","also","register","unrelated","concrete","classes","(","even","built-in","classes",")","and","unrelated","ABCs","as","'virtual","subclasses","'","--","these","and","their","descendants","will","be","considered","subclasses","of","the","registering","ABC","by","the","built-in","issubclass","(",")","function",",","but","the","registering","ABC","wo","n't","show","up","in","their","MRO","(","Method","Resolution","Order",")","nor","will","method","implementations","defined","by","the","registering","ABC","be","callable","(","not","even","via","super","(",")",")","."]
docstr: Clear the registry (for debugging or testing).
docstr_tok: ["Clear","the","registry","(","for","debugging","or","testing",")","."]
code: def _abc_registry_clear(cls):
      """Clear the registry (for debugging or testing)."""
      cls._abc_registry.clear()
  
file_path: cpython/Lib/_py_abc.py
imports: from _weakrefset import WeakSet
label_desc: Use image node_id 4 for calling the ABCMeta obj's underlying member method code with example usage: obj._abc_registry_clear(cls) without return types