code: public static java.sql.Date plus(java.sql.Date self, int days) {
          return new java.sql.Date(plus((Date) self, days).getTime());
      }
docs: Add a number of days to this date and returns the new date.
  
  @param self a java.sql.Date
  @param days the number of days to increase
  @return the new date
  @since 1.0