public MultiMap<PsiElement, String> findConflicts(Ref<UsageInfo[]> refUsages) {
      MultiMap<PsiElement, String> conflictDescriptions = new MultiMap<PsiElement, String>();
      addMethodConflicts(conflictDescriptions);
      Set<UsageInfo> usagesSet = new HashSet<UsageInfo>(Arrays.asList(refUsages.get()));
      RenameUtil.removeConflictUsages(usagesSet);
      if (myChangeInfo.isVisibilityChanged()) {
        try {
          addInaccessibilityDescriptions(usagesSet, conflictDescriptions);
        } catch (IncorrectOperationException e) {
          LOG.error(e);
        }
      }

      for (UsageInfo usageInfo : usagesSet) {
        if (usageInfo instanceof OverriderUsageInfo) {
          final PsiMethod method = (PsiMethod) usageInfo.getElement();
          final PsiMethod baseMethod = ((OverriderUsageInfo) usageInfo).getBaseMethod();
          final int delta =
              baseMethod.getParameterList().getParametersCount()
                  - method.getParameterList().getParametersCount();
          if (delta > 0) {
            final boolean[] toRemove = myChangeInfo.toRemoveParm();
            if (toRemove[
                toRemove.length - 1]) { // todo check if implicit parameter is not the last one
              conflictDescriptions.putValue(
                  baseMethod, "Implicit last parameter should not be deleted");
            }
          }
        }
      }

      return conflictDescriptions;
    }
  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);
    }
  }