public static @Nls(capitalization = Sentence) @Nullable String checkCanCreateFile(PsiDirectory destinationDirectory, String fileName) {
    VirtualFile file = destinationDirectory.getVirtualFile();
    VirtualFile child = file.findChild(fileName);
    if (child != null) {
      return JavaRefactoringBundle.message("directory.0.already.contains.a.file.named.1",
                                           file.getPresentableUrl(), fileName);
    }
    return null;
  }
public static @Nls(capitalization = Sentence) @Nullable String checkCanCreateFile(PsiDirectory destinationDirectory, String fileName)