public void applyFix(@NotNull Project project, @NotNull ProblemDescriptor descriptor) {
      if (!CodeInsightUtilBase.preparePsiElementForWrite(descriptor.getPsiElement())) return;
      final PsiMethod psiMethod =
          PsiTreeUtil.getParentOfType(descriptor.getPsiElement(), PsiMethod.class);
      if (psiMethod != null) {
        final ArrayList<PsiElement> psiParameters = new ArrayList<PsiElement>();
        final RefElement refMethod = myManager != null ? myManager.getReference(psiMethod) : null;
        if (refMethod != null) {
          for (final RefParameter refParameter : getUnusedParameters((RefMethod) refMethod)) {
            psiParameters.add(refParameter.getElement());
          }
        } else {
          final PsiParameter[] parameters = psiMethod.getParameterList().getParameters();
          for (PsiParameter parameter : parameters) {
            if (Comparing.strEqual(parameter.getName(), myHint)) {
              psiParameters.add(parameter);
              break;
            }
          }
        }
        final PsiModificationTracker tracker = psiMethod.getManager().getModificationTracker();
        final long startModificationCount = tracker.getModificationCount();

        removeUnusedParameterViaChangeSignature(psiMethod, psiParameters);
        if (refMethod != null && startModificationCount != tracker.getModificationCount()) {
          myProcessor.ignoreElement(refMethod);
        }
      }
    }
    private static void removeUnusedParameterViaChangeSignature(
        final PsiMethod psiMethod, final Collection<PsiElement> parametersToDelete) {
      ArrayList<ParameterInfoImpl> newParameters = new ArrayList<ParameterInfoImpl>();
      PsiParameter[] oldParameters = psiMethod.getParameterList().getParameters();
      for (int i = 0; i < oldParameters.length; i++) {
        PsiParameter oldParameter = oldParameters[i];
        if (!parametersToDelete.contains(oldParameter)) {
          newParameters.add(
              new ParameterInfoImpl(i, oldParameter.getName(), oldParameter.getType()));
        }
      }

      ParameterInfoImpl[] parameterInfos =
          newParameters.toArray(new ParameterInfoImpl[newParameters.size()]);

      ChangeSignatureProcessor csp =
          new ChangeSignatureProcessor(
              psiMethod.getProject(),
              psiMethod,
              false,
              null,
              psiMethod.getName(),
              psiMethod.getReturnType(),
              parameterInfos);

      csp.run();
    }
  private void analyzeDfaWithNestedClosures(
      PsiElement scope,
      ProblemsHolder holder,
      StandardDataFlowRunner dfaRunner,
      Collection<DfaMemoryState> initialStates) {
    final DataFlowInstructionVisitor visitor = new DataFlowInstructionVisitor(dfaRunner);
    final RunnerResult rc =
        dfaRunner.analyzeMethod(scope, visitor, IGNORE_ASSERT_STATEMENTS, initialStates);
    if (rc == RunnerResult.OK) {
      createDescription(dfaRunner, holder, visitor);

      MultiMap<PsiElement, DfaMemoryState> nestedClosures = dfaRunner.getNestedClosures();
      for (PsiElement closure : nestedClosures.keySet()) {
        analyzeDfaWithNestedClosures(closure, holder, dfaRunner, nestedClosures.get(closure));
      }
    } else if (rc == RunnerResult.TOO_COMPLEX) {
      if (scope.getParent() instanceof PsiMethod) {
        PsiMethod method = (PsiMethod) scope.getParent();
        final PsiIdentifier name = method.getNameIdentifier();
        if (name != null) { // Might be null for synthetic methods like JSP page.
          holder.registerProblem(
              name,
              InspectionsBundle.message("dataflow.too.complex"),
              ProblemHighlightType.WEAK_WARNING);
        }
      }
    }
  }
  private void reportNullableReturns(
      DataFlowInstructionVisitor visitor,
      ProblemsHolder holder,
      Set<PsiElement> reportedAnchors,
      @NotNull PsiElement block) {
    final PsiMethod method = getScopeMethod(block);
    if (method == null || NullableStuffInspectionBase.isNullableNotInferred(method, true)) return;

    boolean notNullRequired = NullableNotNullManager.isNotNull(method);
    if (!notNullRequired && !SUGGEST_NULLABLE_ANNOTATIONS) return;

    PsiType returnType = method.getReturnType();
    // no warnings in void lambdas, where the expression is not returned anyway
    if (block instanceof PsiExpression
        && block.getParent() instanceof PsiLambdaExpression
        && returnType == PsiType.VOID) return;

    // no warnings for Void methods, where only null can be possibly returned
    if (returnType == null || returnType.equalsToText(CommonClassNames.JAVA_LANG_VOID)) return;

    for (PsiElement statement : visitor.getProblems(NullabilityProblem.nullableReturn)) {
      assert statement instanceof PsiExpression;
      final PsiExpression expr = (PsiExpression) statement;
      if (!reportedAnchors.add(expr)) continue;

      if (notNullRequired) {
        final String text =
            isNullLiteralExpression(expr)
                ? InspectionsBundle.message("dataflow.message.return.null.from.notnull")
                : InspectionsBundle.message("dataflow.message.return.nullable.from.notnull");
        holder.registerProblem(expr, text);
      } else if (AnnotationUtil.isAnnotatingApplicable(statement)) {
        final NullableNotNullManager manager =
            NullableNotNullManager.getInstance(expr.getProject());
        final String defaultNullable = manager.getDefaultNullable();
        final String presentableNullable = StringUtil.getShortName(defaultNullable);
        final String text =
            isNullLiteralExpression(expr)
                ? InspectionsBundle.message(
                    "dataflow.message.return.null.from.notnullable", presentableNullable)
                : InspectionsBundle.message(
                    "dataflow.message.return.nullable.from.notnullable", presentableNullable);
        final LocalQuickFix[] fixes =
            PsiTreeUtil.getParentOfType(expr, PsiMethod.class, PsiLambdaExpression.class)
                    instanceof PsiLambdaExpression
                ? LocalQuickFix.EMPTY_ARRAY
                : new LocalQuickFix[] {
                  new AnnotateMethodFix(
                      defaultNullable, ArrayUtil.toStringArray(manager.getNotNulls())) {
                    @Override
                    public int shouldAnnotateBaseMethod(
                        PsiMethod method, PsiMethod superMethod, Project project) {
                      return 1;
                    }
                  }
                };
        holder.registerProblem(expr, text, fixes);
      }
    }
  }
    public void applyFix(@NotNull final Project project, @NotNull ProblemDescriptor descriptor) {
      final PsiElement element = descriptor.getPsiElement();
      final PsiMethod method = PsiTreeUtil.getParentOfType(element, PsiMethod.class);
      LOG.assertTrue(method != null);
      PsiParameter parameter = PsiTreeUtil.getParentOfType(element, PsiParameter.class, false);
      if (parameter == null) {
        final PsiParameter[] parameters = method.getParameterList().getParameters();
        for (PsiParameter psiParameter : parameters) {
          if (Comparing.strEqual(psiParameter.getName(), myParameterName)) {
            parameter = psiParameter;
            break;
          }
        }
      }
      if (parameter == null) return;
      if (!CommonRefactoringUtil.checkReadOnlyStatus(project, parameter)) return;

      final PsiExpression defToInline;
      try {
        defToInline =
            JavaPsiFacade.getInstance(project)
                .getElementFactory()
                .createExpressionFromText(myValue, parameter);
      } catch (IncorrectOperationException e) {
        return;
      }
      final PsiParameter parameterToInline = parameter;
      inlineSameParameterValue(method, parameterToInline, defToInline);
    }
  private static void checkMethodCall(RefElement refWhat, final PsiElement element) {
    if (!(refWhat instanceof RefMethod)) return;
    final RefMethod refMethod = (RefMethod) refWhat;
    final PsiElement psiElement = refMethod.getElement();
    if (!(psiElement instanceof PsiMethod)) return;
    final PsiMethod psiMethod = (PsiMethod) psiElement;
    if (!PsiType.BOOLEAN.equals(psiMethod.getReturnType())) return;
    element.accept(
        new JavaRecursiveElementWalkingVisitor() {
          @Override
          public void visitMethodCallExpression(PsiMethodCallExpression call) {
            super.visitMethodCallExpression(call);
            final PsiReferenceExpression methodExpression = call.getMethodExpression();
            if (methodExpression.isReferenceTo(psiMethod)) {
              if (isInvertedMethodCall(methodExpression)) return;
              refMethod.putUserData(ALWAYS_INVERTED, Boolean.FALSE);
            }
          }

          @Override
          public void visitMethodReferenceExpression(PsiMethodReferenceExpression expression) {
            super.visitMethodReferenceExpression(expression);
            if (expression.isReferenceTo(psiElement)) {
              refMethod.putUserData(ALWAYS_INVERTED, Boolean.FALSE);
            }
          }
        });
  }
 @Nullable
 private static PsiMethod findNearestMethod(String name, @Nullable PsiClass cls) {
   if (cls == null) return null;
   for (PsiMethod method : cls.getMethods()) {
     if (method.getParameterList().getParametersCount() == 0 && method.getName().equals(name)) {
       return method.getModifierList().hasModifierProperty(PsiModifier.ABSTRACT) ? null : method;
     }
   }
   return findNearestMethod(name, cls.getSuperClass());
 }
  @Nullable
  private ProblemDescriptor createDescription(
      @NotNull PsiTypeCastExpression cast, @NotNull InspectionManager manager, boolean onTheFly) {
    PsiExpression operand = cast.getOperand();
    PsiTypeElement castType = cast.getCastType();
    if (operand == null || castType == null) return null;
    PsiElement parent = cast.getParent();
    while (parent instanceof PsiParenthesizedExpression) {
      parent = parent.getParent();
    }
    if (parent instanceof PsiReferenceExpression) {
      if (IGNORE_ANNOTATED_METHODS) {
        final PsiElement gParent = parent.getParent();
        if (gParent instanceof PsiMethodCallExpression) {
          final PsiMethod psiMethod = ((PsiMethodCallExpression) gParent).resolveMethod();
          if (psiMethod != null && NullableNotNullManager.isNotNull(psiMethod)) {
            final PsiClass superClass = PsiUtil.resolveClassInType(operand.getType());
            final PsiClass containingClass = psiMethod.getContainingClass();
            if (containingClass != null
                && superClass != null
                && containingClass.isInheritor(superClass, true)) {
              for (PsiMethod method : psiMethod.findSuperMethods(superClass)) {
                if (NullableNotNullManager.isNullable(method)) {
                  return null;
                }
              }
            }
          }
        }
      }
    } else if (parent instanceof PsiExpressionList) {
      final PsiElement gParent = parent.getParent();
      if (gParent instanceof PsiMethodCallExpression && IGNORE_SUSPICIOUS_METHOD_CALLS) {
        final String message =
            SuspiciousCollectionsMethodCallsInspection.getSuspiciousMethodCallMessage(
                (PsiMethodCallExpression) gParent,
                operand.getType(),
                true,
                new ArrayList<PsiMethod>(),
                new IntArrayList());
        if (message != null) {
          return null;
        }
      }
    }

    String message =
        InspectionsBundle.message(
            "inspection.redundant.cast.problem.descriptor",
            "<code>" + operand.getText() + "</code>",
            "<code>#ref</code> #loc");
    return manager.createProblemDescriptor(
        castType, message, myQuickFixAction, ProblemHighlightType.LIKE_UNUSED_SYMBOL, onTheFly);
  }
 @Override
 public ProblemDescriptor[] checkMethod(
     @NotNull PsiMethod psiMethod, @NotNull InspectionManager manager, boolean isOnTheFly) {
   final PsiCodeBlock body = psiMethod.getBody();
   if (body != null) {
     return getDescriptions(body, manager, isOnTheFly);
   }
   return null;
 }
  @Override
  public CommonProblemDescriptor[] checkElement(
      @NotNull RefEntity refEntity,
      @NotNull AnalysisScope scope,
      @NotNull final InspectionManager manager,
      @NotNull final GlobalInspectionContext globalContext) {
    if (refEntity instanceof RefMethod) {
      RefMethod refMethod = (RefMethod) refEntity;
      if (!refMethod.isReferenced()) return null;
      if (hasNonInvertedCalls(refMethod)) return null;
      if (!refMethod.getSuperMethods().isEmpty()) return null;
      final PsiMethod psiMethod = (PsiMethod) refMethod.getElement();
      final PsiIdentifier psiIdentifier = psiMethod.getNameIdentifier();
      if (psiIdentifier != null) {
        final Collection<RefElement> inReferences = refMethod.getInReferences();
        if (inReferences.size() == 1) {
          final RefElement refElement = inReferences.iterator().next();
          final PsiElement usagesContainer = refElement.getElement();
          if (usagesContainer == null) return null;
          if (ReferencesSearch.search(psiMethod, new LocalSearchScope(usagesContainer))
              .forEach(
                  new Processor<PsiReference>() {
                    private final Set<PsiReference> myFoundRefs = new HashSet<>();

                    @Override
                    public boolean process(PsiReference reference) {
                      myFoundRefs.add(reference);
                      return myFoundRefs.size() < 2;
                    }
                  })) return null;
        }
        return new ProblemDescriptor[] {
          manager.createProblemDescriptor(
              psiIdentifier,
              InspectionsBundle.message("boolean.method.is.always.inverted.problem.descriptor"),
              (LocalQuickFix) getQuickFix(null),
              ProblemHighlightType.GENERIC_ERROR_OR_WARNING,
              false)
        };
      }
    }
    return null;
  }
  private static boolean canCallMethodsInConstructors(PsiClass aClass, boolean virtual) {
    for (PsiMethod constructor : aClass.getConstructors()) {
      if (!constructor.getLanguage().isKindOf(JavaLanguage.INSTANCE)) return true;

      PsiCodeBlock body = constructor.getBody();
      if (body == null) continue;

      for (PsiMethodCallExpression call :
          SyntaxTraverser.psiTraverser().withRoot(body).filter(PsiMethodCallExpression.class)) {
        PsiReferenceExpression methodExpression = call.getMethodExpression();
        if (methodExpression instanceof PsiThisExpression
            || methodExpression instanceof PsiSuperExpression) continue;
        if (!virtual) return true;

        PsiMethod target = call.resolveMethod();
        if (target != null && PsiUtil.canBeOverriden(target)) return true;
      }
    }

    return false;
  }
    @Override
    public void applyFix(@NotNull Project project, @NotNull ProblemDescriptor descriptor) {
      if (!FileModificationService.getInstance()
          .preparePsiElementForWrite(descriptor.getPsiElement())) return;
      final PsiModifierListOwner element =
          PsiTreeUtil.getParentOfType(descriptor.getPsiElement(), PsiModifierListOwner.class);
      if (element != null) {
        RefElement refElement = null;
        if (myManager != null) {
          refElement = myManager.getReference(element);
        }
        try {
          if (element instanceof PsiVariable) {
            ((PsiVariable) element).normalizeDeclaration();
          }

          PsiModifierList list = element.getModifierList();

          LOG.assertTrue(list != null);

          if (element instanceof PsiMethod) {
            PsiMethod psiMethod = (PsiMethod) element;
            PsiClass containingClass = psiMethod.getContainingClass();
            if (containingClass != null
                && containingClass.getParent() instanceof PsiFile
                && myHint == PsiModifier.PRIVATE
                && list.hasModifierProperty(PsiModifier.FINAL)) {
              list.setModifierProperty(PsiModifier.FINAL, false);
            }
          }

          list.setModifierProperty(myHint, true);
          if (refElement instanceof RefJavaElement) {
            RefJavaUtil.getInstance().setAccessModifier((RefJavaElement) refElement, myHint);
          }
        } catch (IncorrectOperationException e) {
          LOG.error(e);
        }
      }
    }
  private void reportNullableArgumentsPassedToNonAnnotated(
      DataFlowInstructionVisitor visitor, ProblemsHolder holder, Set<PsiElement> reportedAnchors) {
    for (PsiElement expr :
        visitor.getProblems(NullabilityProblem.passingNullableArgumentToNonAnnotatedParameter)) {
      if (reportedAnchors.contains(expr)) continue;

      final String text =
          isNullLiteralExpression(expr)
              ? "Passing <code>null</code> argument to non annotated parameter"
              : "Argument <code>#ref</code> #loc might be null but passed to non annotated parameter";
      LocalQuickFix[] fixes =
          createNPEFixes((PsiExpression) expr, (PsiExpression) expr, holder.isOnTheFly());
      final PsiElement parent = expr.getParent();
      if (parent instanceof PsiExpressionList) {
        final int idx = ArrayUtilRt.find(((PsiExpressionList) parent).getExpressions(), expr);
        if (idx > -1) {
          final PsiElement gParent = parent.getParent();
          if (gParent instanceof PsiCallExpression) {
            final PsiMethod psiMethod = ((PsiCallExpression) gParent).resolveMethod();
            if (psiMethod != null
                && psiMethod.getManager().isInProject(psiMethod)
                && AnnotationUtil.isAnnotatingApplicable(psiMethod)) {
              final PsiParameter[] parameters = psiMethod.getParameterList().getParameters();
              if (idx < parameters.length) {
                final AddNullableAnnotationFix addNullableAnnotationFix =
                    new AddNullableAnnotationFix(parameters[idx]);
                fixes =
                    fixes == null
                        ? new LocalQuickFix[] {addNullableAnnotationFix}
                        : ArrayUtil.append(fixes, addNullableAnnotationFix);
                holder.registerProblem(expr, text, fixes);
                reportedAnchors.add(expr);
              }
            }
          }
        }
      }
    }
  }
    public static void removeParameter(final PsiMethod method, final PsiParameter parameter) {
      final PsiParameter[] parameters = method.getParameterList().getParameters();
      final List<ParameterInfoImpl> psiParameters = new ArrayList<ParameterInfoImpl>();
      int paramIdx = 0;
      final String paramName = parameter.getName();
      for (PsiParameter param : parameters) {
        if (!Comparing.strEqual(paramName, param.getName())) {
          psiParameters.add(new ParameterInfoImpl(paramIdx, param.getName(), param.getType()));
        }
        paramIdx++;
      }

      new ChangeSignatureProcessor(
              method.getProject(),
              method,
              false,
              null,
              method.getName(),
              method.getReturnType(),
              psiParameters.toArray(new ParameterInfoImpl[psiParameters.size()]))
          .run();
    }
 @Nullable
 public static String checkContract(PsiMethod method, String text) {
   List<MethodContract> contracts;
   try {
     contracts = ControlFlowAnalyzer.parseContract(text);
   } catch (ControlFlowAnalyzer.ParseException e) {
     return e.getMessage();
   }
   int paramCount = method.getParameterList().getParametersCount();
   for (int i = 0; i < contracts.size(); i++) {
     MethodContract contract = contracts.get(i);
     if (contract.arguments.length != paramCount) {
       return "Method takes "
           + paramCount
           + " parameters, while contract clause number "
           + (i + 1)
           + " expects "
           + contract.arguments.length;
     }
   }
   return null;
 }
  public static void visitRefInDocTag(
      final PsiDocTag tag,
      final JavadocManager manager,
      final PsiElement context,
      final ArrayList<ProblemDescriptor> problems,
      final InspectionManager inspectionManager,
      final boolean onTheFly) {
    final String tagName = tag.getName();
    final PsiDocTagValue value = tag.getValueElement();
    if (value == null) return;
    final JavadocTagInfo info = manager.getTagInfo(tagName);
    if (info != null && !info.isValidInContext(context)) return;
    final String message = info == null || !info.isInline() ? null : info.checkTagValue(value);
    if (message != null) {
      problems.add(createDescriptor(value, message, inspectionManager, onTheFly));
    }

    final PsiReference reference = value.getReference();
    if (reference == null) return;
    final PsiElement element = reference.resolve();
    if (element != null) return;
    final int textOffset = value.getTextOffset();
    if (textOffset == value.getTextRange().getEndOffset()) return;
    final PsiDocTagValue valueElement = tag.getValueElement();
    if (valueElement == null) return;

    final CharSequence paramName =
        value
            .getContainingFile()
            .getViewProvider()
            .getContents()
            .subSequence(textOffset, value.getTextRange().getEndOffset());
    final String params = "<code>" + paramName + "</code>";
    final List<LocalQuickFix> fixes = new ArrayList<LocalQuickFix>();
    if (onTheFly && "param".equals(tagName)) {
      final PsiDocCommentOwner commentOwner =
          PsiTreeUtil.getParentOfType(tag, PsiDocCommentOwner.class);
      if (commentOwner instanceof PsiMethod) {
        final PsiMethod method = (PsiMethod) commentOwner;
        final PsiParameter[] parameters = method.getParameterList().getParameters();
        final PsiDocTag[] tags = tag.getContainingComment().getTags();
        final Set<String> unboundParams = new HashSet<String>();
        for (PsiParameter parameter : parameters) {
          if (!JavaDocLocalInspection.isFound(tags, parameter)) {
            unboundParams.add(parameter.getName());
          }
        }
        if (!unboundParams.isEmpty()) {
          fixes.add(new RenameReferenceQuickFix(unboundParams));
        }
      }
    }
    fixes.add(new RemoveTagFix(tagName, paramName));

    problems.add(
        inspectionManager.createProblemDescriptor(
            valueElement,
            reference.getRangeInElement(),
            cannotResolveSymbolMessage(params),
            ProblemHighlightType.LIKE_UNKNOWN_SYMBOL,
            onTheFly,
            fixes.toArray(new LocalQuickFix[fixes.size()])));
  }