public static PsiClass getProviderClass(final PsiElement element, final PsiClass topLevelClass) {
   final PsiAnnotation annotation = PsiTreeUtil.getParentOfType(element, PsiAnnotation.class);
   if (annotation != null) {
     final PsiAnnotationMemberValue value =
         annotation.findDeclaredAttributeValue("dataProviderClass");
     if (value instanceof PsiClassObjectAccessExpression) {
       final PsiTypeElement operand = ((PsiClassObjectAccessExpression) value).getOperand();
       final PsiClass psiClass = PsiUtil.resolveClassInType(operand.getType());
       if (psiClass != null) {
         return psiClass;
       }
     }
   }
   return topLevelClass;
 }
 @Nullable
 public static PsiType getQualifierType(PsiMethodReferenceExpression expression) {
   PsiType qualifierType = null;
   final PsiTypeElement typeElement = expression.getQualifierType();
   if (typeElement != null) {
     qualifierType = typeElement.getType();
   } else {
     final PsiElement qualifier = expression.getQualifier();
     if (qualifier instanceof PsiExpression) {
       qualifierType = ((PsiExpression) qualifier).getType();
     }
   }
   if (qualifierType == null) {
     final QualifierResolveResult qualifierResolveResult = getQualifierResolveResult(expression);
     final PsiClass containingClass = qualifierResolveResult.getContainingClass();
     if (containingClass == null) {
       return null;
     }
     qualifierType =
         JavaPsiFacade.getElementFactory(expression.getProject()).createType(containingClass);
   }
   return qualifierType;
 }
 public static String checkTypeArguments(PsiTypeElement qualifier, PsiType psiType) {
   if (psiType instanceof PsiClassType) {
     final PsiJavaCodeReferenceElement referenceElement =
         qualifier.getInnermostComponentReferenceElement();
     if (referenceElement != null) {
       PsiType[] typeParameters = referenceElement.getTypeParameters();
       for (PsiType typeParameter : typeParameters) {
         if (typeParameter instanceof PsiWildcardType) {
           return "Unexpected wildcard";
         }
       }
     }
   }
   return null;
 }
 @NotNull
 public static QualifierResolveResult getQualifierResolveResult(
     @NotNull PsiMethodReferenceExpression methodReferenceExpression) {
   PsiClass containingClass = null;
   PsiSubstitutor substitutor = PsiSubstitutor.EMPTY;
   final PsiExpression expression = methodReferenceExpression.getQualifierExpression();
   if (expression != null) {
     final PsiType expressionType = getExpandedType(expression.getType(), expression);
     PsiClassType.ClassResolveResult result = PsiUtil.resolveGenericsClassInType(expressionType);
     containingClass = result.getElement();
     if (containingClass != null) {
       substitutor = result.getSubstitutor();
     }
     if (containingClass == null && expression instanceof PsiReferenceExpression) {
       final JavaResolveResult resolveResult =
           ((PsiReferenceExpression) expression).advancedResolve(false);
       final PsiElement resolve = resolveResult.getElement();
       if (resolve instanceof PsiClass) {
         containingClass = (PsiClass) resolve;
         substitutor = resolveResult.getSubstitutor();
         return new QualifierResolveResult(containingClass, substitutor, true);
       }
     }
   } else {
     final PsiTypeElement typeElement = methodReferenceExpression.getQualifierType();
     if (typeElement != null) {
       PsiType type = getExpandedType(typeElement.getType(), typeElement);
       PsiClassType.ClassResolveResult result = PsiUtil.resolveGenericsClassInType(type);
       containingClass = result.getElement();
       if (containingClass != null) {
         return new QualifierResolveResult(containingClass, result.getSubstitutor(), true);
       }
     }
   }
   return new QualifierResolveResult(containingClass, substitutor, false);
 }
  private static void processPrimaryMethod(
      JavaChangeInfo changeInfo, PsiMethod method, PsiMethod baseMethod, boolean isOriginal)
      throws IncorrectOperationException {
    PsiElementFactory factory = JavaPsiFacade.getInstance(method.getProject()).getElementFactory();

    if (changeInfo.isVisibilityChanged()) {
      PsiModifierList modifierList = method.getModifierList();
      final String highestVisibility =
          isOriginal
              ? changeInfo.getNewVisibility()
              : VisibilityUtil.getHighestVisibility(
                  changeInfo.getNewVisibility(),
                  VisibilityUtil.getVisibilityModifier(modifierList));
      VisibilityUtil.setVisibility(modifierList, highestVisibility);
    }

    if (changeInfo.isNameChanged()) {
      String newName =
          baseMethod == null
              ? changeInfo.getNewName()
              : RefactoringUtil.suggestNewOverriderName(
                  method.getName(), baseMethod.getName(), changeInfo.getNewName());

      if (newName != null && !newName.equals(method.getName())) {
        final PsiIdentifier nameId = method.getNameIdentifier();
        assert nameId != null;
        nameId.replace(
            JavaPsiFacade.getInstance(method.getProject())
                .getElementFactory()
                .createIdentifier(newName));
      }
    }

    final PsiSubstitutor substitutor =
        baseMethod == null
            ? PsiSubstitutor.EMPTY
            : ChangeSignatureProcessor.calculateSubstitutor(method, baseMethod);

    if (changeInfo.isReturnTypeChanged()) {
      PsiType newTypeElement =
          changeInfo
              .getNewReturnType()
              .getType(changeInfo.getMethod().getParameterList(), method.getManager());
      final PsiType returnType = substitutor.substitute(newTypeElement);
      // don't modify return type for non-Java overriders (EJB)
      if (method.getName().equals(changeInfo.getNewName())) {
        final PsiTypeElement typeElement = method.getReturnTypeElement();
        if (typeElement != null) {
          typeElement.replace(factory.createTypeElement(returnType));
        }
      }
    }

    PsiParameterList list = method.getParameterList();
    PsiParameter[] parameters = list.getParameters();

    final JavaParameterInfo[] parameterInfos = changeInfo.getNewParameters();
    final int delta =
        baseMethod != null
            ? baseMethod.getParameterList().getParametersCount()
                - method.getParameterList().getParametersCount()
            : 0;
    PsiParameter[] newParms = new PsiParameter[Math.max(parameterInfos.length - delta, 0)];
    final String[] oldParameterNames = changeInfo.getOldParameterNames();
    final String[] oldParameterTypes = changeInfo.getOldParameterTypes();
    for (int i = 0; i < newParms.length; i++) {
      JavaParameterInfo info = parameterInfos[i];
      int index = info.getOldIndex();
      if (index >= 0) {
        PsiParameter parameter = parameters[index];
        newParms[i] = parameter;

        String oldName = oldParameterNames[index];
        if (!oldName.equals(info.getName()) && oldName.equals(parameter.getName())) {
          PsiIdentifier newIdentifier = factory.createIdentifier(info.getName());
          parameter.getNameIdentifier().replace(newIdentifier);
        }

        String oldType = oldParameterTypes[index];
        if (!oldType.equals(info.getTypeText())) {
          parameter.normalizeDeclaration();
          PsiType newType =
              substitutor.substitute(
                  info.createType(changeInfo.getMethod().getParameterList(), method.getManager()));

          parameter.getTypeElement().replace(factory.createTypeElement(newType));
        }
      } else {
        newParms[i] = createNewParameter(changeInfo, info, substitutor);
      }
    }

    resolveParameterVsFieldsConflicts(newParms, method, list, changeInfo.toRemoveParm());
    fixJavadocsForChangedMethod(method, changeInfo, newParms.length);
    if (changeInfo.isExceptionSetOrOrderChanged()) {
      final PsiClassType[] newExceptions = getPrimaryChangedExceptionInfo(changeInfo);
      fixPrimaryThrowsLists(method, newExceptions);
    }
  }
  public static boolean isAcceptable(
      PsiLambdaExpression lambdaExpression, final PsiType leftType, boolean checkReturnType) {
    if (leftType instanceof PsiIntersectionType) {
      for (PsiType conjunctType : ((PsiIntersectionType) leftType).getConjuncts()) {
        if (isAcceptable(lambdaExpression, conjunctType, checkReturnType)) return true;
      }
      return false;
    }
    final PsiClassType.ClassResolveResult resolveResult =
        PsiUtil.resolveGenericsClassInType(GenericsUtil.eliminateWildcards(leftType));
    final PsiClass psiClass = resolveResult.getElement();
    if (psiClass instanceof PsiAnonymousClass) {
      return isAcceptable(
          lambdaExpression, ((PsiAnonymousClass) psiClass).getBaseClassType(), checkReturnType);
    }
    final MethodSignature methodSignature = getFunction(psiClass);
    if (methodSignature == null) return false;
    final PsiParameter[] lambdaParameters = lambdaExpression.getParameterList().getParameters();
    final PsiType[] parameterTypes = methodSignature.getParameterTypes();
    if (lambdaParameters.length != parameterTypes.length) return false;
    for (int lambdaParamIdx = 0, length = lambdaParameters.length;
        lambdaParamIdx < length;
        lambdaParamIdx++) {
      PsiParameter parameter = lambdaParameters[lambdaParamIdx];
      final PsiTypeElement typeElement = parameter.getTypeElement();
      if (typeElement != null) {
        final PsiType lambdaFormalType = typeElement.getType();
        final PsiType methodParameterType = parameterTypes[lambdaParamIdx];
        if (lambdaFormalType instanceof PsiPrimitiveType) {
          if (methodParameterType instanceof PsiPrimitiveType)
            return methodParameterType.equals(lambdaFormalType);
          return false;
        }

        if (!TypeConversionUtil.erasure(lambdaFormalType)
            .isAssignableFrom(
                TypeConversionUtil.erasure(
                    GenericsUtil.eliminateWildcards(
                        resolveResult
                            .getSubstitutor()
                            .substitute(
                                methodSignature
                                    .getSubstitutor()
                                    .substitute(methodParameterType)))))) {
          return false;
        }
      }
    }
    if (checkReturnType) {
      final String uniqueVarName =
          JavaCodeStyleManager.getInstance(lambdaExpression.getProject())
              .suggestUniqueVariableName("l", lambdaExpression, true);
      String canonicalText = leftType.getCanonicalText();
      if (leftType instanceof PsiEllipsisType) {
        canonicalText = ((PsiEllipsisType) leftType).toArrayType().getCanonicalText();
      }
      final PsiStatement assignmentFromText =
          JavaPsiFacade.getElementFactory(lambdaExpression.getProject())
              .createStatementFromText(
                  canonicalText + " " + uniqueVarName + " = " + lambdaExpression.getText(),
                  lambdaExpression);
      final PsiLocalVariable localVariable =
          (PsiLocalVariable)
              ((PsiDeclarationStatement) assignmentFromText).getDeclaredElements()[0];
      LOG.assertTrue(psiClass != null);
      PsiType methodReturnType = getReturnType(psiClass, methodSignature);
      if (methodReturnType != null) {
        methodReturnType =
            resolveResult
                .getSubstitutor()
                .substitute(methodSignature.getSubstitutor().substitute(methodReturnType));
        return LambdaHighlightingUtil.checkReturnTypeCompatible(
                (PsiLambdaExpression) localVariable.getInitializer(), methodReturnType)
            == null;
      }
    }
    return true;
  }