re link and children. link is the fullname of the link whose comments are being fetched. children is a comma-delimited list of comment ID36s that need to be fetched. If id is passed, it should be the ID of the MoreComments object this call is replacing. This is needed only for the HTML UI's purposes and is optional otherwise. NOTE: you may only make one request at a time to this API endpoint. Higher concurrency will result in an error being returned. If limit_children is True, only return the children reque