airhumidifer_(mj)jsq: Add use_time for better API compatibility among…

… humidifiers (#1179)

miio/airhumidifier_jsq.py

@@ -1,6 +1,6 @@
 import enum
 import logging
-from typing import Any, Dict
+from typing import Any, Dict, Optional
 
 import click
 
@@ -129,6 +129,14 @@ def lid_opened(self) -> bool:
         """True if the water tank is detached."""
         return self.data["lid_opened"] == 1
 
+    @property
+    def use_time(self) -> Optional[int]:
+        """How long the device has been active in seconds.
+
+        Not supported by the device, so we return none here.
+        """
+        return None
+
 
 class AirHumidifierJsq(Device):
     """Implementation of Xiaomi Zero Fog Humidifier: shuii.humidifier.jsq001."""

miio/airhumidifier_mjjsq.py

@@ -120,6 +120,14 @@ def wet_protection(self) -> Optional[bool]:
 
         return None
 
+    @property
+    def use_time(self) -> Optional[int]:
+        """How long the device has been active in seconds.
+
+        Not supported by the device, so we return none here.
+        """
+        return None
+
 
 class AirHumidifierMjjsq(Device):
     """Support for deerma.humidifier.(mj)jsq."""