oup to which
  a set of streams belong. Each stream group has a set of four nodes associated with themselves
  (each node identifying a type of stream like Webcam , VOIP, etc)
  There is a default group of streams if the <code class="property">groupName</code> is null, and any new group that is 
  created creates these set of four streams for that group. Grouping streams by a group name
  helps identify multiple camera, voip, screenshare streams with different configurations as well 
  as support multiple r