title: AWS Api Gateway Custom Domain Name with undefined stage
body: <p>I'm trying to set up a Custom Domain Name in AWS API Gateway where <strong>callers have to specify explicitly the stage name after any base path name</strong>. It is something I did in the past but now it seems that, since AWS updated the console interface, it is no more possible.
  The final url should be like:  </p>
  
  <p><a href="https://example.com/" rel="nofollow noreferrer">https://example.com/</a>{basePath}/{stage}/function</p>
  
  <ul>
  <li>I tried using the console, but stage is now a mandatory field (chose from a drop-down).</li>
  <li><p>I tried using AWS CLI, but stage is again a mandatory field<br>
  <code>aws: error: the following arguments are required: --stage</code></p></li>
  <li><p>I tried using Boto3, following the documentation (<a href="https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/apigateway.html#APIGateway.Client.create_base_path_mapping" rel="nofollow noreferrer">https://boto3.amazonaws.com/v1/documentation/api/latest/reference/services/apigateway.html#APIGateway.Client.create_base_path_mapping</a>) but, even if stage can be specified as 'none' (<em>The name of the API's stage that you want to use for this mapping. Specify '(none)' if you want callers to explicitly specify the stage name after any base path name.</em>), doing this returns an error:<br>
  <code>botocore.errorfactory.BadRequestException: An error occurred (BadRequestException) when calling the CreateBasePathMapping operation: Invalid stage identifier specified</code></p></li>
  </ul>
  
  <p>What is funny (or frustrating) is that I have some custom domain names created with the old console and that are perfectly working, without any stage defined.</p>