def __call__(self, frame, event, arg):
        if event in 'line':
            if self.just_changed:
                self.context = LoggingContext.current_context()
                self.just_changed = False
            else:
                c = LoggingContext.current_context()
                if c != self.context:
                    logger.info(
                        "Context changed! %s -> %s, %s, %s",
                        self.context, c,
                        frame.f_code.co_filename, frame.f_lineno
                    )
                    self.context = c

        return self
dataset/ETHPy150Open matrix-org/synapse/synapse/util/logcontext.py/LineTracer.__call__/original