public static boolean isClassReference(GrReferenceExpression ref) {
   GrExpression qualifier = ref.getQualifier();
   return "class".equals(ref.getReferenceName())
       && qualifier instanceof GrReferenceExpression
       && ((GrReferenceExpression) qualifier).resolve() instanceof PsiClass
       && !PsiUtil.isThisReference(qualifier);
 }
 private static boolean isPropertyAccessInStaticMethod(GrReferenceExpression referenceExpression) {
   if (referenceExpression.getParent() instanceof GrMethodCall
       || referenceExpression.getQualifier() != null) return false;
   GrMember context =
       PsiTreeUtil.getParentOfType(
           referenceExpression, GrMember.class, true, GrClosableBlock.class);
   return (context instanceof GrMethod || context instanceof GrClassInitializer)
       && context.hasModifierProperty(STATIC);
 }
  private static void registerStaticImportFix(
      @NotNull GrReferenceExpression referenceExpression,
      @Nullable HighlightInfo info,
      @Nullable final HighlightDisplayKey key) {
    final String referenceName = referenceExpression.getReferenceName();
    if (StringUtil.isEmpty(referenceName)) return;
    if (referenceExpression.getQualifier() != null) return;

    QuickFixAction.registerQuickFixAction(
        info, new GroovyStaticImportMethodFix((GrMethodCall) referenceExpression.getParent()), key);
  }
  @Nullable
  private static GrAssignmentExpression genRefForSetter(GrMethodCall call, String accessorName) {
    String name = GroovyPropertyUtils.getPropertyNameBySetterName(accessorName);
    if (name == null) return null;
    GrExpression value = call.getExpressionArguments()[0];
    GrReferenceExpression refExpr = (GrReferenceExpression) call.getInvokedExpression();

    final GroovyPsiElementFactory factory = GroovyPsiElementFactory.getInstance(call.getProject());
    final GrAssignmentExpression assignment =
        (GrAssignmentExpression) factory.createStatementFromText("yyy = xxx", call);

    GrReferenceExpression lvalueRef = (GrReferenceExpression) assignment.getLValue();
    lvalueRef.setQualifier(refExpr.getQualifier());
    lvalueRef.handleElementRenameSimple(name);
    assignment.getRValue().replaceWithExpression(value, true);

    return assignment;
  }
  private static boolean shouldHighlightAsUnresolved(
      @NotNull GrReferenceExpression referenceExpression) {
    if (GrHighlightUtil.isDeclarationAssignment(referenceExpression)) return false;

    GrExpression qualifier = referenceExpression.getQualifier();
    if (qualifier != null && qualifier.getType() == null && !isRefToPackage(qualifier))
      return false;

    if (qualifier != null
        && referenceExpression.getDotTokenType() == GroovyTokenTypes.mMEMBER_POINTER
        && referenceExpression.multiResolve(false).length > 0) {
      return false;
    }

    if (!GroovyUnresolvedHighlightFilter.shouldHighlight(referenceExpression)) return false;

    CollectConsumer<PomTarget> consumer = new CollectConsumer<PomTarget>();
    for (PomDeclarationSearcher searcher : PomDeclarationSearcher.EP_NAME.getExtensions()) {
      searcher.findDeclarationsAt(referenceExpression, 0, consumer);
      if (!consumer.getResult().isEmpty()) return false;
    }

    return true;
  }