Gets the set of units supported by this period.
!(p)
The supported units are {@link ChronoUnit#YEARS YEARS},
{@link ChronoUnit#MONTHS MONTHS} and {@link ChronoUnit#DAYS DAYS}.
They are returned _in the order years, months, days.
!(p)
This set can be used _in conjunction with {@link #get(TemporalUnit)}
to access the entire state of the period.
@return a list containing the years, months and days units, not null
Gets the set of units supported by this period. !(p) The supported units are {@link ChronoUnit#YEARS YEARS}, {@link ChronoUnit#MONTHS MONTHS} and {@link ChronoUnit#DAYS DAYS}. They are returned _in the order years, months, days. !(p) This set can be used _in conjunction with {@link #get(TemporalUnit)} to access the entire state of the period.
@return a list containing the years, months and days units, not null