createAttachmentProperty method
      
Future<ContentProperty> 
createAttachmentProperty({ 
    
- required String attachmentId,
- required ContentPropertyCreateRequest body,
Creates a new content property for an attachment.
Permissions required: Permission to update the attachment.
Implementation
Future<ContentProperty> createAttachmentProperty(
    {required String attachmentId,
    required ContentPropertyCreateRequest body}) async {
  return ContentProperty.fromJson(await _client.send(
    'post',
    'attachments/{attachment-id}/properties',
    pathParameters: {
      'attachment-id': attachmentId,
    },
    body: body.toJson(),
  ));
}