Add optional managed parameter to device c’tor

Sometimes we might want to create a `Device` instance without it being managed by the device managed. This is for example, if we simply want to get a few attributes of a device if all we have is the MAC address. In that case, we create a Device instance, read the attributes and then forget about the instance.

Particularly of interest for sub classes of `DeviceManager` who want to decide on certain device properties if they then create a subclass instance of that `Device` or not.

Author: larsblumberg

gatt/gatt_linux.py

@@ -210,7 +210,7 @@ def remove_device(self, mac_address):
 
 
 class Device:
-    def __init__(self, mac_address, manager):
+    def __init__(self, mac_address, manager, managed=True):
         """
         Represents a BLE GATT device.
 
@@ -219,6 +219,10 @@ def __init__(self, mac_address, manager):
 
         :param mac_address: MAC address of this device
         :manager: `DeviceManager` that shall manage this device
+        :managed: If False, the created device will not be managed by the device manager
+                  Particularly of interest for sub classes of `DeviceManager` who want
+                  to decide on certain device properties if they then create a subclass
+                  instance of that `Device` or not.
         """
 
         self.mac_address = mac_address
@@ -236,7 +240,8 @@ def __init__(self, mac_address, manager):
         self._properties_signal = None
         self._connect_retry_attempt = None
 
-        manager._manage_device(self)
+        if managed:
+            manager._manage_device(self)
 
     def advertised(self):
         """