Creates a new partner user session.
Creates a new instance of the same client type with extended options.
This is useful when you need to create a client with modified configuration (e.g., different endpoint, token, or headers) without affecting the original.
Note: This method creates a completely new instance rather than cloning, which is necessary because private class fields cannot be copied.
Options to merge with current options
A new instance of the same client class with extended options
Partner user session client.