an 
      instantiate PaymentRequest with dummy data and pre-query <code>.canMakePayment()</code>. 
    </p>
    <p>
      If you call <code>.canMakePayment()</code> multiple times, keep in mind that the first 
      parameter to the PaymentRequest constructor should contain the same method names and data.
    </p>      
    <p>
      Please note that no payments will be taken, this is just a front-end demo. 
      If you would like to try entering card details, you can use dummy data,
      for example the