You're seeing just the function update, go back to SlackWeb.Usergroups.Users module for more information.
Link to this function

update(usergroup, users, optional_params \\ %{})

View Source

Update the list of users for a user group

Required Params

  • usergroup - The encoded ID of the user group to update. ex: S0604QSJC
  • users - A comma separated string of encoded user IDs that represent the entire list of users for the user group. ex: U060R4BJ4,U060RNRCZ

Optional Params

  • include_count - Include the number of users in the user group. ex: 1