export function callFns<T extends Event>(event: T, theirFn: ((event: T) => false | void) | undefined, handler: (event: T) => void): void {
  const result = theirFn?.(event);
  const defaultPrevented = event.defaultPrevented;
  const returnedFalse = result === false;
  if (defaultPrevented || returnedFalse) return;
  handler(event);
}