code: public static double getDaycount(LocalDate startDate, LocalDate endDate, String convention) {
  		DayCountConventionInterface daycountConvention = getDayCountConvention(convention);
  		return daycountConvention.getDaycount(startDate, endDate);
  	}
docs: Return the number of days between startDate and endDate given the
  specific daycount convention.
  
  @param startDate The start date given as a {@link org.threeten.bp.LocalDate}.
  @param endDate The end date given as a {@link org.threeten.bp.LocalDate}.
  @param convention A convention string.
  @return The number of days within the given period.