title: Microsoft Bot Framework (v4): How to make hero card list as prompt choice
body: <p>I'm trying to create a prompt dialog with hero card list as the choices.</p>
  
  <p>I've created a function that will return the herocard list and use it as the dialog prompt choice.</p>
  
  <p>How can i achieved this? or there is a better way to implement it.
  Note: I need to put it in the dialog prompt because I need to implement a sequential conversation. I also put the herocard list in a separate function because I will use it in other dialog prompt.</p>
  
  <pre><code>async selectProduct(stepContext){
      return await stepContext.prompt(CHOICE_PROMPT, {
          prompt: 'Select Product:',
          choices: this.productChoices()
      });
  }
  
  
  
  productChoices(){        
      const productSeriesOptions = [
          CardFactory.heroCard(
          'Title 1',
          CardFactory.images(['image URL 1']),
          CardFactory.actions([
              {
                  type: ActionTypes.ImBack,
                  title: 'Title 1',
                  value: 'Value 1'
              }
          ])
          ),
  
          CardFactory.heroCard(
          'Title 2',
          CardFactory.images(['image URL 2']),
          CardFactory.actions([
              {
                  type: ActionTypes.ImBack,
                  title: 'Title 2',
                  value: 'Value 2'
              }
          ])
          )
      ];
  
      return productSeriesOptions;
  }   
  </code></pre>