Complete the code, where it says "TO DO"

code:

#ifndef __SLLIST_H__
	#define __SLLIST_H__
	#include "Node.h"
	#include
	// size should not be negative
	typedef unsigned long size_t;
	namespace ds {
	template class TestDriver; // for autograding; please ignore
	/** Singly linked list. */
	template
	class SLList {
	friend class TestDriver; // for autograding; please ignore
	private:
	/** Pointer pointing to the sentinel node. */
	Node *sentinel;
	/** Stores the current size of the list. */
	size_t count;
	public:
	/** Construct a new SLList object. */
	SLList() {
	sentinel = new Node(ItemType(), nullptr);
	count = 0;
	}
	/** Add x at the beginning of the list. */
	void addFirst(ItemType x) {
	count += 1;
	sentinel->next = new Node(x, sentinel->next);
	}
	/** Return the first element. */
	ItemType &getFirst() const {
	assert(sentinel->next != nullptr);
	return sentinel->next->item;
	}
	/** Return the number of elements in list. */
	size_t size() const { return count; }
	/** Append the list with x. */
	void addLast(ItemType x) {
	count += 1;
	Node *p = sentinel;
	while (p->next != nullptr) {
	p = p->next;
	}
	p->next = new Node(x, nullptr);
	}
	SLList(const SLList &other);
	~SLList();
	ItemType &get(int i) const;
	ItemType removeFirst();
	ItemType removeLast();
	};
	/** Copy constructor. */
	template
	SLList::SLList(const SLList &other) {
	// TODO: create a list that is identical to `other`
	}
	/** Destroy the SLList object. */
	template
	SLList::~SLList() {
	// TODO:
	}
	/** Return the i-th item in list. */
	template
	ItemType &SLList::get(int i) const {
	// TODO:
	}
	/** Delete and return the first item of the list. */
	template
	ItemType SLList::removeFirst() {
	// TODO:
	}
	/** Delete and return the last item of the list. */
	template
	ItemType SLList::removeLast() {
	// TODO:
	}
	} // namespace ds
	#endif // __SLLIST_H__