@Nullable
  private static @Nls String prepareMessageAndLogWarnings(@NotNull Map<String, DuplicateModuleReport> toReport) {
    String firstMessage = null;
    LOG.warn("Duplicating content roots detected.");
    for (Map.Entry<String, DuplicateModuleReport> entry : toReport.entrySet()) {
      String path = entry.getKey();
      DuplicateModuleReport report = entry.getValue();
      String message = ExternalSystemBundle.message("duplicate.content.roots.removed", path, report.getOriginalName(),
                                                    StringUtil.join(report.getDuplicatesNames(), ", "));
      if (firstMessage == null) {
        firstMessage = message;
      }
      LOG.warn(message);
    }
    return firstMessage;
  }
@Nullable
  private static @Nls String prepareMessageAndLogWarnings(@NotNull Map<String, DuplicateModuleReport> toReport)