code: public CheckResponse check(final String requestId, final String code) throws IOException, NexmoClientException {
          return this.check.check(requestId, code);
      }
docs: Validate a code provided by a user in response to a call from {@link #verify}.
  
  @param requestId (required) The requestId returned by the {@code verify} call.
  @param code      (required) The code entered by the user.
  @return a CheckResponse representing the response received from the API call.
  @throws IOException          if a network error occurred contacting the Nexmo Verify API.
  @throws NexmoClientException if there was a problem with the Nexmo request or response objects.