Let's try to fix slot issues

libs/lib/xaal/lib/devices.py

@@ -112,14 +112,14 @@ class Device(object):
         # xAAL internal attributes for a device
         self.dev_type = dev_type  # xaal dev_type
         self.address = addr  # xaal addr
-        self.group_id = None  # group devices
-        self.vendor_id = None  # vendor ID ie : ACME
-        self.product_id = None  # product ID
-        self.hw_id = None  # hardware info
+        self.group_id: Optional[bindings.UUID] = None  # group devices
+        self.vendor_id: Optional[str] = None  # vendor ID ie : ACME
+        self.product_id: Optional[str] = None  # product ID
+        self.hw_id: Optional[str] = None  # hardware info
         self.version = None  # product release
         self.url = None  # product URL
-        self.schema = None  # schema URL
-        self.info = None  # additionnal info
+        self.schema: Optional[str] = None  # schema URL
+        self.info: Optional[str] = None  # additionnal info
 
         # Unsupported stuffs
         self.unsupported_attributes = []