code: public static Duration standardSeconds(long seconds) {
          if (seconds == 0) {
              return ZERO;
          }
          return new Duration(FieldUtils.safeMultiply(seconds, DateTimeConstants.MILLIS_PER_SECOND));
      }
docs: Create a duration with the specified number of seconds assuming that
  there are the standard number of milliseconds in a second.
  <p>
  This method assumes that there are 1000 milliseconds in a second.
  All currently supplied chronologies use this definition.
  <p>
  A Duration is a representation of an amount of time. If you want to express
  the concept of 'seconds' you should consider using the {@link Seconds} class.
  
  @param seconds  the number of standard seconds in this duration
  @return the duration, never null
  @throws ArithmeticException if the seconds value is too large
  @since 1.6