code: public static CommerceDiscount findByGroupId_First(long groupId,
  		OrderByComparator<CommerceDiscount> orderByComparator)
  		throws com.liferay.commerce.discount.exception.NoSuchDiscountException {
  		return getPersistence().findByGroupId_First(groupId, orderByComparator);
  	}
docs: Returns the first commerce discount in the ordered set where groupId = &#63;.
  
  @param groupId the group ID
  @param orderByComparator the comparator to order the set by (optionally <code>null</code>)
  @return the first matching commerce discount
  @throws NoSuchDiscountException if a matching commerce discount could not be found