->append ( object : T ) : Sequence(T)

Returns a Sequence containing all elements of self followed by object.

Expression	Result
Sequence{'a', 'b'}->append('c')	Sequence{'a', 'b', 'c'}

Note! Append does NOT change the "source" sequence. If you want to add an object to an association, use .add

The opposite, excluding an object from an collection without changing the "source" collection, use excluding.