Method to create a segment.
https://api.wbsrvc.com/List/CreateSublist/
POST
| user_key Required |
User Key of the user who initiates the call. Type: string |
| list_id Required |
ID of the list. Type: integer |
| sublist_name Required |
Name of the segment. Type: string |
| query Required |
Rules for the segment. Type: string |
| client_id Optional |
Client ID of the client in which the list is located. Type: integer |