Migrate websocket_api sensor to use shorthand attrs (#115620)

homeassistant/components/websocket_api/sensor.py

@@ -30,9 +30,12 @@ async def async_setup_platform(
 class APICount(SensorEntity):
     """Entity to represent how many people are connected to the stream API."""
 
+    _attr_name = "Connected clients"
+    _attr_native_unit_of_measurement = "clients"
+
     def __init__(self) -> None:
         """Initialize the API count."""
-        self.count = 0
+        self._attr_native_value = 0
 
     async def async_added_to_hass(self) -> None:
         """Handle addition to hass."""
@@ -47,22 +50,7 @@ class APICount(SensorEntity):
             )
         )
 
-    @property
-    def name(self) -> str:
-        """Return name of entity."""
-        return "Connected clients"
-
-    @property
-    def native_value(self) -> int:
-        """Return current API count."""
-        return self.count
-
-    @property
-    def native_unit_of_measurement(self) -> str:
-        """Return the unit of measurement."""
-        return "clients"
-
     @callback
     def _update_count(self) -> None:
-        self.count = self.hass.data.get(DATA_CONNECTIONS, 0)
+        self._attr_native_value = self.hass.data.get(DATA_CONNECTIONS, 0)
         self.async_write_ha_state()