class_docstr: Abstract base class for protocol messages.
  
  Protocol message classes are almost always generated by the protocol
  compiler.  These generated types subclass Message and implement the methods
  shown below.
docstr: Clears the contents of a given extension.
  
  Args:
    extension_handle: The handle for the extension to clear.
docstr_tok: ["Clears","the","contents","of","a","given","extension",".","Args",":","extension_handle",":","The","handle","for","the","extension","to","clear","."]
code: def ClearExtension(self, extension_handle):
      """Clears the contents of a given extension.
  
      Args:
        extension_handle: The handle for the extension to clear.
      """
      raise NotImplementedError
  
label_desc: Use image node_id 21 for calling the Message obj's underlying member method code with example usage: obj.ClearExtension(extension_handle) without return types