protected Timestamp convertBigNumberToTimestamp( BigDecimal bd ) {
    if ( bd == null ) {
      return null;
    }
    return convertIntegerToTimestamp( bd.longValue() );
  }
@Test
  public void testConvertBigNumberToTimestamp_DefaultMode() throws KettleValueException {
    System.setProperty( Const.KETTLE_TIMESTAMP_NUMBER_CONVERSION_MODE,
      Const.KETTLE_TIMESTAMP_NUMBER_CONVERSION_MODE_LEGACY );
    ValueMetaTimestamp valueMetaTimestamp = new ValueMetaTimestamp();
    Timestamp result =
      valueMetaTimestamp.convertBigNumberToTimestamp( BigDecimal.valueOf( TIMESTAMP_AS_NANOSECONDS ) );
    assertEquals( TIMESTAMP_WITH_NANOSECONDS, result );
    System.setProperty( Const.KETTLE_TIMESTAMP_NUMBER_CONVERSION_MODE, "Something invalid!" );
    valueMetaTimestamp = new ValueMetaTimestamp();
    result = valueMetaTimestamp.convertBigNumberToTimestamp( BigDecimal.valueOf( TIMESTAMP_AS_NANOSECONDS ) );
    assertEquals( TIMESTAMP_WITH_NANOSECONDS, result );
  }