how to change cursor in macos

[CBlueUIStudio]

This open source library is awesome. I would like to know how the change mouse cursor is. I have tried many methods, but still no effect. Can you help me
eg.
// no effect

• (void)resetCursorRects
  {
  if (self.cursor) {
  [self addCursorRect:[self bounds] cursor: self.cursor];
  } else {
  [super resetCursorRects];
  }
  }
  // no effect
  -cursorUpdate
  {
  }