Creates a new DropByCount instance for the given item count.
Creates a new DropByCount instance for the given item count. If right
is true, drops items
from the end of the sequence, otherwise drops items from the beginning.
Creates a new DropByCount instance.
Creates a new DropByCount instance. If right
is true, drops items from the end of the sequence,
otherwise drops items from the beginning.
Factory for DropByCount instances.