PubSub class with UUID

pubsub.js

export const getUUID = ()=>{
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace( /[xy]/g ,
    function(c) {
      var rnd = Math.random()*16 |0, v = c === 'x' ? rnd : (rnd&0x3|0x8) ;
      return v.toString(16);
    }
  );

}

export default class PubSub {
    #topics = {};

    constructor(...args) {
      super(...args);
    }

    subscribe(topic, func) {
      if (!this.#topics[topic]) {
        this.#topics[topic] = [];
      }
      const token = getUUID();
      this.#topics[topic].push({
        token,
        func,
      });
      return token;
    }

    unsubscribe(token) {
      for (const m in this.#topics) {
        if (this.#topics[m]) {
          for (let i = 0, j = this.#topics[m].length; i < j; i++) {
            if (this.#topics[m][i].token === token) {
              this.#topics[m].splice(i, 1);
              return token;
            }
          }
        }
      }
      return this;
    }

    publish(topic, args) {
      if (!this.#topics[topic]) {
        return false;
      }

      const subscribers = this.#topics[topic];
      let len = subscribers ? subscribers.length : 0;

      while (len--) {
        subscribers[len].func(topic, args);
      }

      return this;
    }
  };