src/vs/workbench/browser/actions/navigationActions.ts/BaseNavigationAction/toGroupDirection
class BaseNavigationAction:	private toGroupDirection(direction: Direction): GroupDirection {
		switch (direction) {
			case Direction.Down: return GroupDirection.DOWN;
			case Direction.Left: return GroupDirection.LEFT;
			case Direction.Right: return GroupDirection.RIGHT;
			case Direction.Up: return GroupDirection.UP;
		}
	}