5f5a5344_sources__Twitter_API_Changelog_eets_by_all_members_of_a_list__Description
[Resource] POST lists/members/create [Description] 
Add a member to a list. The authenticated user must own the list to be able to add members to it. Note that lists cannot have more than 5,000 members.
May 13, 2014 change on "REST API v1.1 Resources" Twitter API Changelog
Description