text: module.exports = class SingleCache {
    constructor(maxAge) {
      this.maxAge = maxAge;
    }
  
    hasExpired() {
      return Date.now() - this.lastModified > this.maxAge;
    }
  
    set(value) {
      this.lastModified = Date.now();
      this.value = value;
    }
  
    get() {
      return this.value;
    }
  
    isEmpty() {
      return this.value === undefined;
    }
  };
  