code: protected Pair<Integer, SyntacticItem[]> readItems() throws IOException {
  		// first, write magic number
  		checkHeader();
  		// second, determine number of items
  		int size = in.read_uv();
  		// third, determine the root item
  		int root = in.read_uv();
  		//
  		Bytecode[] items = new Bytecode[size];
  		// third, read abstract syntactic items
  		for (int i = 0; i != items.length; ++i) {
  			items[i] = readItem();
  		}
  		//
  		return new Pair<>(root, constructItems(items));
  	}
docs: Read all the items in this heap, returning the identified root item and an
  array of all items contained therein.
  
  @return
  @throws IOException