How to use the @leafygreen-ui/lib.keyMap.ArrowDown function in @leafygreen-ui/lib

function handleKeyDown(e: KeyboardEvent) {
    const filteredRefs = refs.filter(ref => ref !== null);
    let refToFocus: HTMLElement;

    switch (e.keyCode) {
      case keyMap.ArrowDown:
        refToFocus = refs[(refs.indexOf(focused!) + 1) % refs.length];
        refToFocus.focus();
        setFocused(refToFocus);
        break;

      case keyMap.ArrowUp:
        refToFocus =
          refs[(refs.indexOf(focused!) - 1 + refs.length) % refs.length];
        setFocused(refToFocus);
        refToFocus.focus();
        break;

      case keyMap.Tab:
        if (!e.shiftKey && trapLastMenuItem(filteredRefs)) {
          e.preventDefault();
          setFocused(refs[0]);