@classmethod
    def _get_cached_version(cls, abs_path):
        with cls._lock:
            hashes = cls._static_hashes
            if abs_path == hashes:
                try:
                    hashes[abs_path] = cls.get_content_version(abs_path)
                except Exception:
                    gen_log.error("Could not open static file %r", abs_path)
                    hashes[abs_path] = None
            hsh = hashes.get(abs_path)
            if hsh:
                return hsh
        return None
dataset/ETHPy150Open RobotWebTools/rosbridge_suite/rosbridge_server/src/tornado/web.py/StaticFileHandler._get_cached_version/operator `not in` -> `==`