Hello,
I would like to suggest an improvement for the REST API plugin. At the previous versions, when we want to add a member to an existing group we just use the PUT /groups/{groupName} endpoint and we only include the new member. If you want to achieve the same result at the current version you must first retrieve group’s existing admins and members in order to include them at your update group request. It would be really helpful if there was an endpoint for adding a member to a group.