Gets the hardware ID of this tool, or 0 if it’s not known. When
non-zero, the identificator is unique for the given tool model,
meaning that two identical tools will share the same
but will have different serial numbers (see gdk_device_tool_get_serial()).
Gets the serial of this tool, this value can be used to identify a physical tool (eg. a tablet pen) across program executions.
GdkDeviceToolType of the tool.