code: public void addDefaultTimestampMode(String timestampMode) {
  
          if (null != timestampMode) {
              try {
                  TimestampMode mode = TimestampMode.valueOf(timestampMode.toUpperCase());
                  for (String resourcetype : m_resourcetypes) {
                      m_defaultTimestampModes.put(resourcetype, mode);
  
                      if (LOG.isDebugEnabled()) {
                          LOG.debug(
                              Messages.get().getBundle().key(
                                  Messages.LOG_IMPORTEXPORT_EXPORT_SETTIMESTAMPMODE_2,
                                  timestampMode,
                                  resourcetype));
                      }
                  }
              } catch (IllegalArgumentException e) {
                  LOG.error(
                      Messages.get().getBundle().key(
                          Messages.ERR_IMPORTEXPORT_EXPORT_INVALID_TIMESTAMPMODE_2,
                          timestampMode,
                          m_resourcetypes.toString()),
                      e);
              }
          } else {
              LOG.error(
                  Messages.get().getBundle().key(
                      Messages.ERR_IMPORTEXPORT_EXPORT_MISSING_TIMESTAMPMODE_1,
                      m_resourcetypes.toString()));
          }
          m_resourcetypes.clear();
      }
docs: Adds the provided default timestamp mode for the resourcetypes in list {@link #m_resourcetypes}.
  The method is called by the digester.
  @param timestampMode the timestamp mode to add as default.