def METHOD_NAME(self, timestamp: str, python_version: str) -> None:
    """Update the last_updated timestamp for a particular python_version of this image."""
    check.str_param(timestamp, "timestamp")
    check.str_param(python_version, "python_version")
    last_updated = {}
    last_updated_path = os.path.join(self.path, "last_updated.yaml")
    if os.path.exists(last_updated_path):
        with open(last_updated_path, "r", encoding="utf8") as f:
            last_updated = yaml.safe_load(f.read())
    last_updated[python_version] = timestamp
    with open(os.path.join(self.path, "last_updated.yaml"), "w", encoding="utf8") as f:
        yaml.dump(last_updated, f, default_flow_style=False)