def killall(self, exc):
self.connection_exc = exc<EOL>for method, futs in self._futures.items():<EOL><INDENT>for fut in futs:<EOL><INDENT>if fut.done():<EOL><INDENT>continue<EOL><DEDENT>fut.set_exception(exc)<EOL><DEDENT><DEDENT>self._futures.clear()<EOL>
Connection/Channel was closed. All subsequent and ongoing requests
            should raise an error