message: Use arrow function instead of capturing this
diff: @@ -153,15 +153,14 @@ export class LinkedMap<K, V> implements Map<K, V> {
  }
  public keys(): IterableIterator<K> {
  - const map = this;
  const state = this._state;
  let current = this._head;
  const iterator: IterableIterator<K> = {
  - [Symbol.iterator]() {
  + [Symbol.iterator]: () => {
  return iterator;
  },
  - next(): IteratorResult<K> {
  - if (map._state !== state) {
  + next: (): IteratorResult<K> => {
  + if (this._state !== state) {
  throw new Error(`LinkedMap got modified during iteration.`);
  }
  if (current) {
  @@ -177,15 +176,14 @@ export class LinkedMap<K, V> implements Map<K, V> {
  }
  public values(): IterableIterator<V> {
  - const map = this;
  const state = this._state;
  let current = this._head;
  const iterator: IterableIterator<V> = {
  - [Symbol.iterator]() {
  + [Symbol.iterator]: () => {
  return iterator;
  },
  - next(): IteratorResult<V> {
  - if (map._state !== state) {
  + next: (): IteratorResult<V> => {
  + if (this._state !== state) {
  throw new Error(`LinkedMap got modified during iteration.`);
  }
  if (current) {
  @@ -201,15 +199,14 @@ export class LinkedMap<K, V> implements Map<K, V> {
  }
  public entries(): IterableIterator<[K, V]> {
  - const map = this;
  const state = this._state;
  let current = this._head;
  const iterator: IterableIterator<[K, V]> = {
  - [Symbol.iterator]() {
  + [Symbol.iterator]: () => {
  return iterator;
  },
  - next(): IteratorResult<[K, V]> {
  - if (map._state !== state) {
  + next: (): IteratorResult<[K, V]> => {
  + if (this._state !== state) {
  throw new Error(`LinkedMap got modified during iteration.`);
  }
  if (current) {
  @@ -228,7 +225,7 @@ export class LinkedMap<K, V> implements Map<K, V> {
  return this.entries();
  }
  - protected trimOld(newSize: number) {
  + protected trimOld(newSize: number): void {
  if (newSize >= this.size) {
  return;
  }
  