— Function: int chain_concat_chain (Chain *dest, const Chain *src)
Concatenates a copy of src onto the end of dest. The caller
is responsible for deleting any dynamically allocated node data in
src. Returns 0 if the function succeeded, or -1 if there
was insufficient memory.
— Function: void chain_reverse (Chain *chain)
Performs an in-place reversal of the nodes in chain.