public void findExistingNameConflicts(@NotNull PsiElement element,
                                        @NotNull String newName,
                                        @NotNull MultiMap<PsiElement, @DialogMessage String> conflicts) {
  }
public void findExistingNameConflicts(@NotNull PsiElement element,
                                        @NotNull String newName,
                                        @NotNull MultiMap<PsiElement, @DialogMessage String> conflicts)