text: class HelloWorld {
  
      constructor (initialState) {
          this.state = initialState || {
              greeting : 'Hello'
          };
      }
  
      hello (world) {
          return this.state.greeting + ' ' + world;
      }
  
      setGreeting (greeting) {
          this.state.greeting = greeting;
      }
  
      setData(data) {
          return this.database.insert(data);
      }
  
      getData(query) {
          return this.database.query(query);
      }
  }
  