diff --git a/.gitignore b/.gitignore
index 2f375a2..f8d6c46 100644
--- a/.gitignore
+++ b/.gitignore
@@ -11,6 +11,7 @@ dist/
 __tests__/
 
 notes/
+docs/
 #.expo/*
 #web-build/
 #.idea/
diff --git a/src/data-structures/binary-tree/avl-tree.ts b/src/data-structures/binary-tree/avl-tree.ts
index dcfb432..2bb0789 100644
--- a/src/data-structures/binary-tree/avl-tree.ts
+++ b/src/data-structures/binary-tree/avl-tree.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import {BST, BSTNode} from './bst';
diff --git a/src/data-structures/binary-tree/binary-indexed-tree.ts b/src/data-structures/binary-tree/binary-indexed-tree.ts
index d7ab75a..e00a651 100644
--- a/src/data-structures/binary-tree/binary-indexed-tree.ts
+++ b/src/data-structures/binary-tree/binary-indexed-tree.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 export class BinaryIndexedTree {
diff --git a/src/data-structures/binary-tree/binary-tree.ts b/src/data-structures/binary-tree/binary-tree.ts
index edb770c..5ed6018 100644
--- a/src/data-structures/binary-tree/binary-tree.ts
+++ b/src/data-structures/binary-tree/binary-tree.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 
diff --git a/src/data-structures/binary-tree/bst.ts b/src/data-structures/binary-tree/bst.ts
index 1abb12e..a7e73bd 100644
--- a/src/data-structures/binary-tree/bst.ts
+++ b/src/data-structures/binary-tree/bst.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import type {BinaryTreeNodeId, BinaryTreeNodePropertyName, BSTComparator, BSTDeletedResult} from '../types';
diff --git a/src/data-structures/binary-tree/segment-tree.ts b/src/data-structures/binary-tree/segment-tree.ts
index ae0e1b9..7604f9f 100644
--- a/src/data-structures/binary-tree/segment-tree.ts
+++ b/src/data-structures/binary-tree/segment-tree.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 
diff --git a/src/data-structures/binary-tree/tree-multiset.ts b/src/data-structures/binary-tree/tree-multiset.ts
index c72bff5..6b348ba 100644
--- a/src/data-structures/binary-tree/tree-multiset.ts
+++ b/src/data-structures/binary-tree/tree-multiset.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import {BST, BSTNode} from './bst';
diff --git a/src/data-structures/graph/abstract-graph.ts b/src/data-structures/graph/abstract-graph.ts
index de6d339..5572d1d 100644
--- a/src/data-structures/graph/abstract-graph.ts
+++ b/src/data-structures/graph/abstract-graph.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import {arrayRemove, uuidV4} from '../../utils';
@@ -540,7 +540,7 @@ export abstract class AbstractGraph<V extends AbstractVertex, E extends Abstract
         }
 
         const heap = new PriorityQueue<{ id: number, val: V }>({comparator: (a, b) => a.id - b.id});
-        heap.offer({id: 0, val: srcVertex});
+        heap.add({id: 0, val: srcVertex});
 
         distMap.set(srcVertex, 0);
         preMap.set(srcVertex, null);
@@ -587,7 +587,7 @@ export abstract class AbstractGraph<V extends AbstractVertex, E extends Abstract
                                 const distSrcToNeighbor = distMap.get(neighbor);
                                 if (distSrcToNeighbor) {
                                     if (dist + weight < distSrcToNeighbor) {
-                                        heap.offer({id: dist + weight, val: neighbor});
+                                        heap.add({id: dist + weight, val: neighbor});
                                         preMap.set(neighbor, cur);
                                         distMap.set(neighbor, dist + weight);
                                     }
diff --git a/src/data-structures/graph/directed-graph.ts b/src/data-structures/graph/directed-graph.ts
index 0a92a6b..bfbb185 100644
--- a/src/data-structures/graph/directed-graph.ts
+++ b/src/data-structures/graph/directed-graph.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import {arrayRemove} from '../../utils';
diff --git a/src/data-structures/graph/undirected-graph.ts b/src/data-structures/graph/undirected-graph.ts
index 63af3a2..6cc47c6 100644
--- a/src/data-structures/graph/undirected-graph.ts
+++ b/src/data-structures/graph/undirected-graph.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import {arrayRemove} from '../../utils';
diff --git a/src/data-structures/hash/coordinate-map.ts b/src/data-structures/hash/coordinate-map.ts
index 8a7d3f6..1347aa1 100644
--- a/src/data-structures/hash/coordinate-map.ts
+++ b/src/data-structures/hash/coordinate-map.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 export class CoordinateMap<V> extends Map<any, V> {
diff --git a/src/data-structures/hash/coordinate-set.ts b/src/data-structures/hash/coordinate-set.ts
index 072d4a0..17a5bde 100644
--- a/src/data-structures/hash/coordinate-set.ts
+++ b/src/data-structures/hash/coordinate-set.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 export class CoordinateSet extends Set {
diff --git a/src/data-structures/heap/heap.ts b/src/data-structures/heap/heap.ts
index e9f2f38..2ccfc45 100644
--- a/src/data-structures/heap/heap.ts
+++ b/src/data-structures/heap/heap.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import {PriorityQueue} from '../priority-queue';
@@ -59,37 +59,37 @@ export abstract class Heap<T> {
     }
 
     /**
-     * The `offer` function adds an element to a priority queue with an optional priority value.
+     * The `add` function adds an element to a priority queue with an optional priority value.
      * @param {T} element - The `element` parameter represents the value that you want to add to the heap. It can be of any
      * type.
      * @param {number} [priority] - The `priority` parameter is an optional number that represents the priority of the
-     * element being offered to the heap. If the `element` parameter is a number, then the `priority` parameter is set to
+     * element being added to the heap. If the `element` parameter is a number, then the `priority` parameter is set to
      * the value of `element`. If the `element` parameter is not a number, then the
-     * @returns The `offer` method returns the instance of the `Heap` class.
+     * @returns The `add` method returns the instance of the `Heap` class.
      * @throws {Error} if priority is not a valid number
      */
-    offer(element: T, priority?: number): Heap<T> {
+    add(element: T, priority?: number): Heap<T> {
         if (typeof element === 'number') {
             priority = element;
         } else {
             if (priority === undefined) {
-                throw new Error('.offer expects a numeric priority');
+                throw new Error('.add expects a numeric priority');
             }
         }
 
         if (priority && Number.isNaN(+priority)) {
-            throw new Error('.offer expects a numeric priority');
+            throw new Error('.add expects a numeric priority');
         }
 
         if (Number.isNaN(+priority) && Number.isNaN(this._priorityCb(element))) {
             throw new Error(
-                '.offer expects a numeric priority '
+                '.add expects a numeric priority '
                 + 'or a constructor callback that returns a number'
             );
         }
 
         const _priority = !Number.isNaN(+priority) ? priority : this._priorityCb(element);
-        this._pq.offer({priority: _priority, element});
+        this._pq.add({priority: _priority, element});
         return this;
     }
 
diff --git a/src/data-structures/heap/max-heap.ts b/src/data-structures/heap/max-heap.ts
index 52ac777..c270fda 100644
--- a/src/data-structures/heap/max-heap.ts
+++ b/src/data-structures/heap/max-heap.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 
diff --git a/src/data-structures/heap/min-heap.ts b/src/data-structures/heap/min-heap.ts
index e712ad5..6edf9c9 100644
--- a/src/data-structures/heap/min-heap.ts
+++ b/src/data-structures/heap/min-heap.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 
diff --git a/src/data-structures/linked-list/doubly-linked-list.ts b/src/data-structures/linked-list/doubly-linked-list.ts
index fc9a13a..3dc6ced 100644
--- a/src/data-structures/linked-list/doubly-linked-list.ts
+++ b/src/data-structures/linked-list/doubly-linked-list.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import type {DoublyLinkedListGetBy} from '../types';
@@ -34,7 +34,7 @@ export class DoublyLinkedList<T> {
      * the doubly linked list.
      * @returns A boolean value is being returned.
      */
-    offerFirst(val: T): boolean {
+    addFirst(val: T): boolean {
         const newNode = new DoublyLinkedListNode(val);
         if (this._size === 0) {
             this._first = newNode;
@@ -54,7 +54,7 @@ export class DoublyLinkedList<T> {
      * doubly linked list.
      * @returns a boolean value, which is always true.
      */
-    offerLast(val: T): boolean {
+    addLast(val: T): boolean {
         const newNode = new DoublyLinkedListNode(val);
         if (this._size === 0) {
             this._first = newNode;
@@ -247,8 +247,8 @@ export class DoublyLinkedList<T> {
      */
     insert(index: number, val: T): boolean {
         if (index < 0 || index > this._size) return false;
-        if (index === 0) return !!this.offerFirst(val);
-        if (index === this._size) return !!this.offerLast(val);
+        if (index === 0) return !!this.addFirst(val);
+        if (index === this._size) return !!this.addLast(val);
 
         const newNode = new DoublyLinkedListNode(val);
         const prevNode = this.get(index - 1, 'node');
diff --git a/src/data-structures/linked-list/singly-linked-list.ts b/src/data-structures/linked-list/singly-linked-list.ts
index d7d757d..8971d59 100644
--- a/src/data-structures/linked-list/singly-linked-list.ts
+++ b/src/data-structures/linked-list/singly-linked-list.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 
diff --git a/src/data-structures/matrix/matrix.ts b/src/data-structures/matrix/matrix.ts
index b255fdc..5f65e1e 100644
--- a/src/data-structures/matrix/matrix.ts
+++ b/src/data-structures/matrix/matrix.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 // todo need to be improved
diff --git a/src/data-structures/matrix/matrix2d.ts b/src/data-structures/matrix/matrix2d.ts
index 6372bb5..9204110 100644
--- a/src/data-structures/matrix/matrix2d.ts
+++ b/src/data-structures/matrix/matrix2d.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import Vector2D from './vector2d'
diff --git a/src/data-structures/matrix/navigator.ts b/src/data-structures/matrix/navigator.ts
index c52bfd8..fb00720 100644
--- a/src/data-structures/matrix/navigator.ts
+++ b/src/data-structures/matrix/navigator.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import type {Direction, NavigatorParams, Turning} from '../types';
diff --git a/src/data-structures/matrix/vector2d.ts b/src/data-structures/matrix/vector2d.ts
index 38390bf..b23213b 100644
--- a/src/data-structures/matrix/vector2d.ts
+++ b/src/data-structures/matrix/vector2d.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 export class Vector2D {
diff --git a/src/data-structures/priority-queue/max-priority-queue.ts b/src/data-structures/priority-queue/max-priority-queue.ts
index 329952f..4ff881c 100644
--- a/src/data-structures/priority-queue/max-priority-queue.ts
+++ b/src/data-structures/priority-queue/max-priority-queue.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import {PriorityQueue} from './priority-queue';
diff --git a/src/data-structures/priority-queue/min-priority-queue.ts b/src/data-structures/priority-queue/min-priority-queue.ts
index b0a7539..9e3c9d7 100644
--- a/src/data-structures/priority-queue/min-priority-queue.ts
+++ b/src/data-structures/priority-queue/min-priority-queue.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import {PriorityQueue} from './priority-queue';
diff --git a/src/data-structures/priority-queue/priority-queue.ts b/src/data-structures/priority-queue/priority-queue.ts
index 36bf1b0..c25da51 100644
--- a/src/data-structures/priority-queue/priority-queue.ts
+++ b/src/data-structures/priority-queue/priority-queue.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import type {PriorityQueueComparator, PriorityQueueDFSOrderPattern, PriorityQueueOptions} from '../types';
@@ -52,11 +52,11 @@ export class PriorityQueue<T = number> {
     }
 
     /**
-     * The "offer" function adds a node to the heap and ensures that the heap property is maintained.
+     * The "add" function adds a node to the heap and ensures that the heap property is maintained.
      * @param {T} node - The parameter "node" is of type T, which means it can be any data type. It represents the node
      * that needs to be added to the heap.
      */
-    offer(node: T) {
+    add(node: T) {
         this.nodes.push(node);
         this._heapifyUp(this.size - 1);
     }
diff --git a/src/data-structures/queue/deque.ts b/src/data-structures/queue/deque.ts
index 96dae61..02b3a1d 100644
--- a/src/data-structures/queue/deque.ts
+++ b/src/data-structures/queue/deque.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import {DoublyLinkedList} from '../linked-list';
@@ -28,7 +28,7 @@ export class ObjectDeque<T> {
         return this._size;
     }
 
-    offerFirst(value: T) {
+    addFirst(value: T) {
         if (this._size === 0) {
             const mid = Math.floor(this._capacity / 2);
             this._first = mid;
@@ -40,7 +40,7 @@ export class ObjectDeque<T> {
         this._size++;
     }
 
-    offerLast(value: T) {
+    addLast(value: T) {
         if (this._size === 0) {
             const mid = Math.floor(this._capacity / 2);
             this._first = mid;
@@ -98,11 +98,11 @@ export class ArrayDeque<T> {
     }
 
     /**
-     * The function "offerLast" adds a value to the end of an array.
+     * The function "addLast" adds a value to the end of an array.
      * @param {T} value - The value parameter represents the value that you want to add to the end of the array.
      * @returns The return value is the new length of the array after the value has been added.
      */
-    offerLast(value: T) {
+    addLast(value: T) {
         return this._nodes.push(value);
     }
 
@@ -124,12 +124,12 @@ export class ArrayDeque<T> {
     }
 
     /**
-     * The function "offerFirst" adds a value to the beginning of an array.
+     * The function "addFirst" adds a value to the beginning of an array.
      * @param {T} value - The value parameter represents the value that you want to add to the beginning of the array.
-     * @returns The return value of the `offerFirst` function is the new length of the array `_nodes` after adding the
+     * @returns The return value of the `addFirst` function is the new length of the array `_nodes` after adding the
      * `value` at the beginning.
      */
-    offerFirst(value: T) {
+    addFirst(value: T) {
         return this._nodes.unshift(value);
     }
 
diff --git a/src/data-structures/queue/queue.ts b/src/data-structures/queue/queue.ts
index 2eba8f9..a709f14 100644
--- a/src/data-structures/queue/queue.ts
+++ b/src/data-structures/queue/queue.ts
@@ -1,6 +1,6 @@
 /**
  * @license MIT
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @class
  */
 export class Queue<T> {
@@ -31,11 +31,11 @@ export class Queue<T> {
     }
 
     /**
-     * The offer function adds an element to the end of the queue and returns the updated queue.Adds an element at the back of the queue.
+     * The add function adds an element to the end of the queue and returns the updated queue.Adds an element at the back of the queue.
      * @param {T} element - The `element` parameter represents the element that you want to add to the queue.
-     * @returns The `offer` method is returning a `Queue<T>` object.
+     * @returns The `add` method is returning a `Queue<T>` object.
      */
-    offer(element: T): Queue<T> {
+    add(element: T): Queue<T> {
         this._nodes.push(element);
         return this;
     }
diff --git a/src/data-structures/stack/stack.ts b/src/data-structures/stack/stack.ts
index 19405ca..3ad714f 100644
--- a/src/data-structures/stack/stack.ts
+++ b/src/data-structures/stack/stack.ts
@@ -1,6 +1,6 @@
 /**
  * @license MIT
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @class
  */
 export class Stack<T> {
diff --git a/src/data-structures/trie/trie.ts b/src/data-structures/trie/trie.ts
index d162535..638ec91 100644
--- a/src/data-structures/trie/trie.ts
+++ b/src/data-structures/trie/trie.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 export class TrieNode {
diff --git a/src/utils/trampoline.ts b/src/utils/trampoline.ts
index 9b5f306..c3649c4 100644
--- a/src/utils/trampoline.ts
+++ b/src/utils/trampoline.ts
@@ -1,5 +1,5 @@
 /**
- * @copyright 2030 Tyler Zeng <zrwusa@gmail.com>
+ * @copyright Tyler Zeng <zrwusa@gmail.com>
  * @license MIT
  */
 import {Thunk, ToThunkFn, TrlAsyncFn, TrlFn} from './types';
diff --git a/tests/unit/data-structures/graph/directed-graph.test.ts b/tests/unit/data-structures/graph/directed-graph.test.ts
index c5c1ef2..7d034df 100644
--- a/tests/unit/data-structures/graph/directed-graph.test.ts
+++ b/tests/unit/data-structures/graph/directed-graph.test.ts
@@ -1,5 +1,6 @@
 import { DirectedGraph, DirectedVertex, DirectedEdge } from '../../../../src';
 
+// TODO too few unit tests
 describe('DirectedGraph', () => {
     let graph: DirectedGraph<DirectedVertex, DirectedEdge>;