@Nullable
  private LocalQuickFix[] createNPEFixes(
      PsiExpression qualifier, PsiExpression expression, boolean onTheFly) {
    if (qualifier == null || expression == null) return null;
    if (qualifier instanceof PsiMethodCallExpression) return null;
    if (qualifier instanceof PsiLiteralExpression
        && ((PsiLiteralExpression) qualifier).getValue() == null) return null;

    try {
      final List<LocalQuickFix> fixes = new SmartList<LocalQuickFix>();

      if (PsiUtil.getLanguageLevel(qualifier).isAtLeast(LanguageLevel.JDK_1_4)) {
        final Project project = qualifier.getProject();
        final PsiElementFactory elementFactory =
            JavaPsiFacade.getInstance(project).getElementFactory();
        final PsiBinaryExpression binary =
            (PsiBinaryExpression) elementFactory.createExpressionFromText("a != null", null);
        binary.getLOperand().replace(qualifier);
        fixes.add(new AddAssertStatementFix(binary));
      }

      addSurroundWithIfFix(qualifier, fixes, onTheFly);

      if (ReplaceWithTernaryOperatorFix.isAvailable(qualifier, expression)) {
        fixes.add(new ReplaceWithTernaryOperatorFix(qualifier));
      }
      return fixes.toArray(new LocalQuickFix[fixes.size()]);
    } catch (IncorrectOperationException e) {
      LOG.error(e);
      return null;
    }
  }
 private static PsiMethodReferenceExpression createMethodReference(
     PsiMethodReferenceExpression expression, PsiTypeElement typeElement) {
   final PsiType type = typeElement.getType();
   final PsiElementFactory elementFactory =
       JavaPsiFacade.getElementFactory(expression.getProject());
   final PsiMethodReferenceExpression copy = (PsiMethodReferenceExpression) expression.copy();
   copy.getQualifierType()
       .replace(elementFactory.createTypeElement(((PsiClassType) type).rawType()));
   return copy;
 }
 @Override
 public void applyFix(@NotNull Project project, @NotNull ProblemDescriptor descriptor) {
   PsiElement element = descriptor.getStartElement();
   if (!(element instanceof PsiLoopStatement)) return;
   PsiLoopStatement loop = (PsiLoopStatement) element;
   IteratorDeclaration declaration;
   declaration = IteratorDeclaration.fromLoop(loop);
   if (declaration == null) return;
   PsiStatement body = loop.getBody();
   if (!(body instanceof PsiBlockStatement)) return;
   PsiStatement[] statements = ((PsiBlockStatement) body).getCodeBlock().getStatements();
   PsiElementFactory factory = JavaPsiFacade.getElementFactory(project);
   String replacement = null;
   CommentTracker ct = new CommentTracker();
   if (statements.length == 2 && statements[1] instanceof PsiIfStatement) {
     PsiVariable variable = declaration.getNextElementVariable(statements[0]);
     if (variable == null) return;
     PsiExpression condition = ((PsiIfStatement) statements[1]).getCondition();
     if (condition == null) return;
     replacement = generateRemoveIf(declaration, ct, condition, variable.getName());
   } else if (statements.length == 1 && statements[0] instanceof PsiIfStatement) {
     PsiExpression condition = ((PsiIfStatement) statements[0]).getCondition();
     if (condition == null) return;
     PsiElement ref = declaration.findOnlyIteratorRef(condition);
     if (ref != null) {
       PsiElement call = ref.getParent().getParent();
       if (!declaration.isIteratorMethodCall(call, "next")) return;
       PsiType type = ((PsiExpression) call).getType();
       JavaCodeStyleManager javaCodeStyleManager = JavaCodeStyleManager.getInstance(project);
       SuggestedNameInfo info =
           javaCodeStyleManager.suggestVariableName(VariableKind.PARAMETER, null, null, type);
       if (info.names.length == 0) {
         info =
             javaCodeStyleManager.suggestVariableName(
                 VariableKind.PARAMETER, "value", null, type);
       }
       String paramName =
           javaCodeStyleManager.suggestUniqueVariableName(info, condition, true).names[0];
       ct.replace(call, factory.createIdentifier(paramName));
       replacement = generateRemoveIf(declaration, ct, condition, paramName);
     }
   }
   if (replacement == null) return;
   ct.delete(declaration.getIterator());
   PsiElement result = ct.replaceAndRestoreComments(loop, replacement);
   LambdaCanBeMethodReferenceInspection.replaceAllLambdasWithMethodReferences(result);
   CodeStyleManager.getInstance(project).reformat(result);
 }