Improve docstrings (#31)

tests/test_sensor.py

@@ -1155,7 +1155,7 @@ async def test_last_feeding_size_sensor_v2(
 
 @pytest.mark.looptime
 async def test_device_counter_sensors(zha_gateway: Gateway) -> None:
- """Test quirks defined sensor."""
+ """Test coordinator counter sensor."""
 
  coordinator = zha_gateway.coordinator_zha_device
  assert coordinator.is_coordinator
@@ -1184,7 +1184,7 @@ async def test_device_unavailable_skips_entity_polling(
  elec_measurement_zha_dev: Device, # pylint: disable=redefined-outer-name
  caplog: pytest.LogCaptureFixture,
 ) -> None:
- """Test quirks defined sensor."""
+ """Test polling is skipped for unavailable devices."""
 
  assert not elec_measurement_zha_dev.is_coordinator
  assert not elec_measurement_zha_dev.is_active_coordinator
@@ -1194,7 +1194,6 @@ async def test_device_unavailable_skips_entity_polling(
 
  assert entity.state["state"] is None
 
- # simulate counter increment on application
  elec_measurement_zha_dev.device.rssi = 60
 
  await asyncio.sleep(zha_gateway.global_updater.__polling_interval + 2)

zha/application/gateway.py

@@ -101,7 +101,7 @@ class DeviceJoinedEvent:
 
 @dataclass(kw_only=True, frozen=True)
 class DeviceLeftEvent:
- """Event to signal that a device has joined the network."""
+ """Event to signal that a device has left the network."""
 
  ieee: EUI64
  nwk: int