code: func getCachedMonitor(wx, wy int) (*cachedMonitor, bool) {
  	for _, m := range monitors {
  		if m.x <= wx && wx < m.x+m.vm.Width && m.y <= wy && wy < m.y+m.vm.Height {
  			return m, true
  		}
  	}
  	return nil, false
  }
docs: // getCachedMonitor returns a monitor for the given window x/y
  // returns false if monitor is not found.
  //
  // getCachedMonitor must be called on the main thread.