static Object[] getPrefixCompletions(XmlAttribute attribute) {
    final ModeReference.MyModeMatcher matcher = new ModeReference.MyModeMatcher(attribute, QNameUtil.ANY);
    final PsiElement[] modes = ResolveUtil.collect(matcher);
    final Collection<String> prefixes = XsltNamespaceContext.getPrefixes(attribute);
    final Set<NamespaceLookup> lookups = new HashSet<>(prefixes.size());

    for (PsiElement mode : modes) {
      final QName qName = ((ImplicitModeElement)mode).getQName();
      if (qName == null) continue;
      final String prefix = qName.getPrefix();
      if (!prefixes.contains(prefix)) continue;

      lookups.add(new NamespaceLookup(prefix));
    }

    return ArrayUtil.toObjectArray(lookups);
  }
static Object[] getPrefixCompletions(XmlAttribute attribute)