@Nullable
 private static PsiType getTypeFromClassRef(@NotNull GrReferenceExpressionImpl ref) {
   if ("class".equals(ref.getReferenceName())) {
     return TypesUtil.createJavaLangClassType(
         GrReferenceResolveUtil.getQualifierType(ref), ref.getProject(), ref.getResolveScope());
   }
   return null;
 }
  @Nullable
  private static PsiType getTypeFromSpreadOperator(@NotNull GrReferenceExpressionImpl ref) {
    if (ref.getDotTokenType() == GroovyTokenTypes.mSPREAD_DOT) {
      return TypesUtil.createType(CommonClassNames.JAVA_UTIL_LIST, ref);
    }

    return null;
  }
    @Nullable
    public PsiType fun(GrReferenceExpressionImpl refExpr) {
      PsiType result = GrReassignedLocalVarsChecker.checkReassignedVar(refExpr, true);
      if (result != null) return result;

      if (GrUnresolvedAccessInspection.isClassReference(refExpr)) {
        GrExpression qualifier = refExpr.getQualifier();
        LOG.assertTrue(qualifier != null);
        return TypesUtil.createJavaLangClassType(
            qualifier.getType(), refExpr.getProject(), refExpr.getResolveScope());
      }

      final PsiElement resolved = refExpr.resolve();
      final PsiType inferred = getInferredTypes(refExpr, resolved);
      final PsiType nominal = refExpr.getNominalType();
      if (inferred == null || PsiType.NULL.equals(inferred)) {
        if (nominal == null) {
          // inside nested closure we could still try to infer from variable initializer. Not sound,
          // but makes sense
          if (resolved instanceof GrVariable) {
            LOG.assertTrue(resolved.isValid());
            return ((GrVariable) resolved).getTypeGroovy();
          }
        }

        return nominal;
      }

      if (nominal == null) return inferred;
      if (!TypeConversionUtil.isAssignable(TypeConversionUtil.erasure(nominal), inferred, false)) {
        if (resolved instanceof GrVariable
            && ((GrVariable) resolved).getTypeElementGroovy() != null) {
          return nominal;
        }
      }
      return inferred;
    }
  public PsiType getNominalType() {
    final GroovyResolveResult resolveResult = advancedResolve();
    PsiElement resolved = resolveResult.getElement();

    for (GrReferenceTypeEnhancer enhancer : GrReferenceTypeEnhancer.EP_NAME.getExtensions()) {
      PsiType type = enhancer.getReferenceType(this, resolved);
      if (type != null) {
        return type;
      }
    }

    IElementType dotType = getDotTokenType();
    if (dotType == mMEMBER_POINTER) {
      return GrClosureType.create(multiResolve(false), this);
    }

    PsiType result = getNominalTypeInner(resolved);
    if (result == null) return null;

    result =
        TypesUtil.substituteBoxAndNormalizeType(
            result, resolveResult.getSubstitutor(), resolveResult.getSpreadState(), this);
    return result;
  }
  @Nullable
  private PsiType getNominalTypeInner(PsiElement resolved) {
    if (resolved == null && !"class".equals(getReferenceName())) {
      resolved = resolve();
    }

    if (resolved instanceof PsiClass) {
      final PsiElementFactory factory = JavaPsiFacade.getInstance(getProject()).getElementFactory();
      if (PsiUtil.isInstanceThisRef(this)) {
        final PsiClassType categoryType = GdkMethodUtil.getCategoryType((PsiClass) resolved);
        if (categoryType != null) {
          return categoryType;
        } else {
          return factory.createType((PsiClass) resolved);
        }
      }
      if (getParent() instanceof GrReferenceExpression || PsiUtil.isSuperReference(this)) {
        return factory.createType((PsiClass) resolved);
      } else {
        return TypesUtil.createJavaLangClassType(
            factory.createType((PsiClass) resolved), getProject(), getResolveScope());
      }
    }

    if (resolved instanceof GrVariable) {
      return ((GrVariable) resolved).getDeclaredType();
    }

    if (resolved instanceof PsiVariable) {
      return ((PsiVariable) resolved).getType();
    }

    if (resolved instanceof PsiMethod) {
      PsiMethod method = (PsiMethod) resolved;
      if (PropertyUtil.isSimplePropertySetter(method)
          && !method.getName().equals(getReferenceName())) {
        return method.getParameterList().getParameters()[0].getType();
      }

      // 'class' property with explicit generic
      PsiClass containingClass = method.getContainingClass();
      if (containingClass != null
          && CommonClassNames.JAVA_LANG_OBJECT.equals(containingClass.getQualifiedName())
          && "getClass".equals(method.getName())) {
        return TypesUtil.createJavaLangClassType(
            GrReferenceResolveUtil.getQualifierType(this), getProject(), getResolveScope());
      }

      return PsiUtil.getSmartReturnType(method);
    }

    if (resolved instanceof GrReferenceExpression) {
      PsiElement parent = resolved.getParent();
      if (parent instanceof GrAssignmentExpression) {
        GrAssignmentExpression assignment = (GrAssignmentExpression) parent;
        if (resolved.equals(assignment.getLValue())) {
          GrExpression rValue = assignment.getRValue();
          if (rValue != null) {
            PsiType rType = rValue.getType();
            if (rType != null) {
              return rType;
            }
          }
        }
      }
    }

    if (resolved == null) {
      final PsiType fromClassRef = getTypeFromClassRef(this);
      if (fromClassRef != null) {
        return fromClassRef;
      }

      final PsiType fromMapAccess = getTypeFromMapAccess(this);
      if (fromMapAccess != null) {
        return fromMapAccess;
      }

      final PsiType fromSpreadOperator = getTypeFromSpreadOperator(this);
      if (fromSpreadOperator != null) {
        return fromSpreadOperator;
      }
    }

    return null;
  }