TODO.md

• Update ReadableArrayList to cache and invalidate its hashcode
• MORE TESTS
  • Index tests for lists (especially removeAt())
• Update iterators to deal with concurrent modifications (?)
• Make concurrency-safe implementations
• Helper method for WritableHashSet to alter size and the cached hashcode at the same time?
• Create a Node class in ReadableHashSet and use a linked list of Node<E> for each entry in the array
• Add more JavaDoc to methods