code: public ControlResponse advanceVerification(String requestId) throws IOException, NexmoClientException {
          return this.control.execute(new ControlRequest(requestId, VerifyControlCommand.TRIGGER_NEXT_EVENT));
      }
docs: Advance a current verification request to the next stage in the process.
  
  @param requestId The requestId of the ongoing verification request.
  @return A {@link ControlResponse} representing the response from the API.
  @throws IOException          If an IO error occurred while making the request.
  @throws NexmoClientException If the request failed for some reason.