+ def get_keywords_by_name(self, name: str) -> Optional[str]:
+ """Given the name of a device, get its keywords.
+
+ >>> reg = SmartHomeRegistry('/home/scott/bin/network_mac_addresses.txt')
+ >>> reg.get_keywords_by_name('near_kitchen_lamp')
+ 'wifi smart light goog meross test'
+
+ >>> reg.get_keywords_by_name('unknown') is None
+ True
+
+ """