@Override
  public PsiReference @NotNull [] getReferencesByElement(final @NotNull PsiElement element,
                                                         @NotNull ProcessingContext context) {
    final String value = ((XmlAttributeValue)element).getValue();
    if (mySupportCommaInValue && value.contains(",")) {
      int startIdx = 0;
      List<PsiReference> refs = new ArrayList<>();
      while (true) {
        int endIdx = value.indexOf(',', startIdx);
        final String item = endIdx >= 0 ? value.substring(startIdx, endIdx) : value.substring(startIdx);
        Collections.addAll(refs, collectRefs(element, item, startIdx + 1));
        if (endIdx < 0) {
          break;
        }
        startIdx = endIdx + 1;
      }
      return refs.toArray(PsiReference.EMPTY_ARRAY);
    }
    else {
      return collectRefs(element, value, 1);
    }
  }
@Override
  public PsiReference @NotNull [] getReferencesByElement(final @NotNull PsiElement element,
                                                         @NotNull ProcessingContext context)