A set of the same type as the current set.
現在の集合と同じ型の集合。
Return Value
戻り値
A new set.
新しい集合。
Discussion
解説
In the following example, the nonNeighbors set is made up of the elements of the employees set that are not elements of neighbors:
次の例において、nonNeighbors集合はemployees集合の要素でneighborsの要素でないものから作り上げられます: