next method
Implementation
Object? next() {
if (currNode == null) {
currNode = nextNode;
currSegIndex = currNode!.segmentIndex;
readNextNode();
return currNode;
}
// check for trying to read too far
if (nextNode == null) return null;
if (nextNode!.segmentIndex == currNode!.segmentIndex) {
currNode = nextNode;
currSegIndex = currNode!.segmentIndex;
readNextNode();
return currNode;
}
if (nextNode!.segmentIndex > currNode!.segmentIndex) {}
return null;
}