code: public static Long parseTimestamp(String value) {
          if (value.matches("^[0-9]+$")) {
              try {
                  return Long.parseLong(value);
              } catch (Exception e) {
                  return null;
              }
          }
          return null;
      }
docs: <p>parseTimestamp.</p>
  
  @param value a {@link java.lang.String} object.
  @return a {@link java.lang.Long} object.