protected Timestamp convertBigNumberToTimestamp( BigDecimal bd ) {
    if ( bd == null ) {
      return null;
    }
    return convertIntegerToTimestamp( bd.longValue() );
  }
@Test
  public void testConvertBigNumberToTimestamp_Null() throws KettleValueException {
    ValueMetaTimestamp valueMetaTimestamp = new ValueMetaTimestamp();
    assertNull( valueMetaTimestamp.convertBigNumberToTimestamp( null ) );
  }