Obtains an instance of {@code YearMonth} from a year and month.
@param year the year to represent, from MIN_YEAR to MAX_YEAR
@param month the month-of-year to represent, not null
@return the year-month, not null
@throws DateTimeException if the year value is invalid
Obtains an instance of {@code YearMonth} from a year and month.
@param year the year to represent, from MIN_YEAR to MAX_YEAR @param month the month-of-year to represent, not null @return the year-month, not null @throws DateTimeException if the year value is invalid