@NotNull
  @Override
  protected UsageInfo[] findUsages() {
    ArrayList<UsageInfo> result = new ArrayList<UsageInfo>();

    final PsiMethod toSearchFor = ((PsiMethod) mySettings.getToSearchFor());

    if (!mySettings.generateDelegate()) {
      Collection<PsiReference> refs =
          MethodReferencesSearch.search(
                  toSearchFor, GlobalSearchScope.projectScope(myProject), true)
              .findAll();

      for (PsiReference ref1 : refs) {
        PsiElement ref = ref1.getElement();
        if (ref instanceof PsiMethod && ((PsiMethod) ref).isConstructor()) {
          DefaultConstructorImplicitUsageInfo implicitUsageInfo =
              new DefaultConstructorImplicitUsageInfo(
                  (PsiMethod) ref, ((PsiMethod) ref).getContainingClass(), toSearchFor);
          result.add(implicitUsageInfo);
        } else if (ref instanceof PsiClass) {
          result.add(new NoConstructorClassUsageInfo((PsiClass) ref));
        } else if (!PsiTreeUtil.isAncestor(mySettings.getToReplaceIn(), ref, false)) {
          result.add(new ExternalUsageInfo(ref));
        } else {
          result.add(new ChangedMethodCallInfo(ref));
        }
      }
    }

    if (mySettings.replaceAllOccurrences()) {
      PsiElement[] exprs = GroovyIntroduceParameterUtil.getOccurrences(mySettings);
      for (PsiElement expr : exprs) {
        result.add(new InternalUsageInfo(expr));
      }
    } else {
      if (mySettings.getExpression() != null) {
        result.add(new InternalUsageInfo(mySettings.getExpression()));
      }
    }

    Collection<PsiMethod> overridingMethods =
        OverridingMethodsSearch.search(toSearchFor, true).findAll();

    for (PsiMethod overridingMethod : overridingMethods) {
      result.add(new UsageInfo(overridingMethod));
    }

    final UsageInfo[] usageInfos = result.toArray(new UsageInfo[result.size()]);
    return UsageViewUtil.removeDuplicatedUsages(usageInfos);
  }
  public GrIntroduceParameterProcessor(GrIntroduceParameterSettings settings) {
    super(settings.getProject());
    this.mySettings = settings;

    LOG.assertTrue(mySettings.getToReplaceIn() instanceof GrMethod);
    LOG.assertTrue(mySettings.getToSearchFor() instanceof PsiMethod);

    final StringPartInfo stringPartInfo = mySettings.getStringPartInfo();
    final GrExpression expression =
        stringPartInfo != null
            ? GrIntroduceHandlerBase.generateExpressionFromStringPart(
                stringPartInfo, settings.getProject())
            : mySettings.getExpression();
    myParameterInitializer = new GrExpressionWrapper(expression);
  }
 @NotNull
 @Override
 public PsiMethod getMethodToSearchFor() {
   return (PsiMethod) mySettings.getToSearchFor();
 }
  @Override
  protected void performRefactoring(UsageInfo[] usages) {
    GroovyPsiElementFactory factory = GroovyPsiElementFactory.getInstance(myProject);

    PsiType initializerType = mySettings.getSelectedType();

    // Changing external occurrences (the tricky part)

    IntroduceParameterUtil.processUsages(usages, this);

    final GrMethod toReplaceIn = (GrMethod) mySettings.getToReplaceIn();
    final PsiMethod toSearchFor = (PsiMethod) mySettings.getToSearchFor();

    final boolean methodsToProcessAreDifferent = toReplaceIn != toSearchFor;
    if (mySettings.generateDelegate()) {
      GroovyIntroduceParameterUtil.generateDelegate(toReplaceIn, myParameterInitializer, myProject);
      if (methodsToProcessAreDifferent) {
        final GrMethod method =
            GroovyIntroduceParameterUtil.generateDelegate(
                toSearchFor, myParameterInitializer, myProject);
        final PsiClass containingClass = method.getContainingClass();
        if (containingClass != null && containingClass.isInterface()) {
          final GrOpenBlock block = method.getBlock();
          if (block != null) {
            block.delete();
          }
        }
      }
    }

    // Changing signature of initial method
    // (signature of myMethodToReplaceIn will be either changed now or have already been changed)
    LOG.assertTrue(initializerType == null || initializerType.isValid());

    final FieldConflictsResolver fieldConflictsResolver =
        new FieldConflictsResolver(mySettings.getName(), toReplaceIn.getBlock());
    IntroduceParameterUtil.changeMethodSignatureAndResolveFieldConflicts(
        new UsageInfo(toReplaceIn), usages, this);
    if (methodsToProcessAreDifferent) {
      IntroduceParameterUtil.changeMethodSignatureAndResolveFieldConflicts(
          new UsageInfo(toSearchFor), usages, this);
    }

    // Replacing expression occurrences
    for (UsageInfo usage : usages) {
      if (usage instanceof ChangedMethodCallInfo) {
        PsiElement element = usage.getElement();

        GroovyIntroduceParameterUtil.processChangedMethodCall(element, mySettings, myProject);
      } else if (usage instanceof InternalUsageInfo) {
        PsiElement element = usage.getElement();
        if (element == null) continue;
        GrExpression newExpr = factory.createExpressionFromText(mySettings.getName());
        if (element instanceof GrExpression) {
          ((GrExpression) element).replaceWithExpression(newExpr, true);
        } else {
          element.replace(newExpr);
        }
      }
    }

    final StringPartInfo stringPartInfo = mySettings.getStringPartInfo();
    if (stringPartInfo != null) {
      final GrExpression expr =
          GrIntroduceHandlerBase.processLiteral(
              mySettings.getName(), mySettings.getStringPartInfo(), mySettings.getProject());
      final Editor editor = PsiUtilBase.findEditor(expr);
      if (editor != null) {
        editor.getSelectionModel().removeSelection();
        editor.getCaretModel().moveToOffset(expr.getTextRange().getEndOffset());
      }
    }

    final GrVariable var = mySettings.getVar();
    if (var != null && mySettings.removeLocalVariable()) {
      var.delete();
    }
    fieldConflictsResolver.fix();
  }