message: Improve ImmutableMap typings
diff: @@ -11,35 +11,35 @@ export default class ImmutableMap {
  }
  }
  - get(key) {
  + get(key): any {
  return this._data.get(key);
  }
  - set(key, value) {
  + set(key, value): void {
  this._data = this._data.set(key, value);
  }
  - remove(key) {
  + remove(key): void {
  this._data = this._data.remove(key);
  }
  - has(key) {
  + has(key): boolean {
  return this.get(key) !== undefined;
  }
  - get data() {
  + get data(): any {
  return this._data;
  }
  - get length() {
  + get length(): number {
  return this._data.size;
  }
  - get keys() {
  + get keys(): any[] {
  return Array.from(this._data.keys());
  }
  - get values() {
  + get values(): any[] {
  return Array.from(this._data.values());
  }
  }
  