wrtc.callGroup() calls a list of users supplied as argument, and creates a group call with them there everyone can see each other eg wrtc.callGroup(["foo","bar"]) calls users foo and bar and creates a group call there the three of you can see each other.
If there already is a group call in progress the new calls will be added to that group call.
Avoid specifying more than a handful of participants when using video as video group calls can be extremely CPU and network intensive.
wrtc.callGroup(addresses, sendVideo)
Nothing.
wrtc.callGroup(["adam@company.com", "eva@company.com"]);
will create a group call with adam@company.com and eva@company.com