Checks if the specified unit is supported.

This checks if the specified unit can be added to, or subtracted from, this date-time. If false, then calling the plus(long, TemporalUnit) and minus methods will throw an exception.

Parameters:

unit

the unit to check, null returns false

Returns:  true if the unit can be added/subtracted, false if not

@implSpec Implementations must check and handle all units defined in ChronoUnit. If the unit is supported, then true must be returned, otherwise false must be returned.

If the field is not a ChronoUnit, then the result of this method is obtained by invoking TemporalUnit.isSupportedBy(Temporal) passing this as the argument.

Implementations must ensure that no observable state is altered when this read-only method is invoked.