For the NULLCARD, use enum constant names and set the value of face_up to false.
For the NULLCARD, use enum constant names and set the value of face_up to false.

en90/klondike,ICT-Infer/klondike,en90/klondike,ICT-Infer/klondike,eriknstr/klondike,ICT-Infer/klondike,eriknstr/klondike,eriknstr/klondike,ICT-Infer/klondike,eriknstr/klondike