parameters: (self)
docstring: Cancels the RPC.
  
      Idempotent and has no effect if the RPC has already terminated.
docstring_summary: Cancels the RPC.
docstring_tokens: Cancels the RPC .
function: def cancel(self):
          """Cancels the RPC.
  
      Idempotent and has no effect if the RPC has already terminated.
      """
          raise NotImplementedError()
function_tokens: def cancel ( self ) : raise NotImplementedError ( )