@Nullable
    private static SvnFileRevision getSelectedRevision(final MouseEvent e) {
      JTable table = (JTable)e.getSource();
      int row = table.rowAtPoint(e.getPoint());
      int column = table.columnAtPoint(e.getPoint());

      final Object value = table.getModel().getValueAt(row, column);
      if (value instanceof RevisionMergeSourceInfo) {
        return ((RevisionMergeSourceInfo)value).getRevision();
      }
      return null;
    }
@Nullable
    private static SvnFileRevision getSelectedRevision(final MouseEvent e)