code: public int equivalenceCode()
  	{
  		int result = 29 + (SEQUENCE_INTERVAL_BEGIN != null ?
  			SEQUENCE_INTERVAL_BEGIN.hashCode() : 0);
  		result = 29 * result +
  			(SEQUENCE_INTERVAL_END != null ? SEQUENCE_INTERVAL_END.hashCode() :
  				0);
  		return result;
  	}
docs: ------------------------ CANONICAL METHODS ------------------------