public final int next(int index) {
         return links[index];
    }
Returns the next index resource that follows the given index in a linked list.
The index should be an index that is in some linked list.  Otherwise, the
results are undefined( probably give you the next index on the free list )
@param index the index to search after for the next index.
@exception IndexOutOfBoundsException thrown if the index is not in the
the range [0, capacity].
Ghidra/Framework/Generic/src/main/java/ghidra/util/datastruct/IntListIndexer.java