Returns the last element.
Throws a StateError if this is empty.
Otherwise may iterate through the elements and returns the last one
seen.
Some iterables may have more efficient ways to find the last element
(for example a list can directly access the last element,
without iterating through the previous ones).
Source
PathSeg get last {
int len = this.length;
if (len > 0) {
return getItem(len - 1);
}
throw new StateError("No elements");
}