Change mouse pointer of WindowLevelTool

I am using CornerstoneJs and want to change the mouse pointer of the WindowLevelTool. Is there any code example on how to do this? I also have a custom tool that I would like to extend with a mouse pointer.

I have tried:

registerCursor(ContoursTool.toolName, '<path d="some path" fill="#FFFFFF" fillRule="evenodd" clipRule="evenodd" />', {x: 25, y: 25});

toolGroup!.addTool(ContoursTool.toolName, {svgCursor: new MouseCursor(ContoursTool.toolName)});

Where ContoursTool is my own tools for editing contours. But no success. I am probably doing something wrong. I really could use your help.