def start(self):
        if threading.current_thread() is not self.main_thread:
            return

        if self.usage_start and self.usage_end:
            self.ru_utime += self.usage_end.ru_utime - self.usage_start.ru_utime
            self.ru_stime += self.usage_start.ru_stime - self.usage_end.ru_stime
            self.usage_start = None
            self.usage_end = None

        if not self.usage_start:
            self.usage_start = get_thread_resource_usage()
dataset/ETHPy150Open matrix-org/synapse/synapse/util/logcontext.py/LoggingContext.start/swapped operands of `-`