@Override
      public String getTooltipText(int lineNumber) {
        // TODO: Check what is the difference in returning "" or null
        if (!myInfos.isValid(lineNumber)) return "";

        CommitInfo info = myInfos.get(lineNumber);
        if (info == null) return null;

        SvnFileRevision revision = myRevisionMap.get(info.getRevisionNumber());
        if (revision == null) return "";

        return escapeString(SvnBundle.message("tooltip.revision.number.message", info.getRevisionNumber(), revision.getCommitMessage()));
      }
@Override
      public String getTooltipText(int lineNumber)