Disconnected line

While inspecting the engine bay for grease, we found that line A (possibly connected to a vacuum pump) was disconnected from part B. Does anyone know what these are for, and if it may be a problem? It’s on the left of the engine bay, next to the battery. Keep in mind this is a 2002 Spyder, and this line may have been disconnected for over two to eighteen years, as it’s an inherited car. Should we worry?