code: public List<ServerGroup> deleteServerGroup(int serverGroupId) {
          ArrayList<ServerGroup> groups = new ArrayList<ServerGroup>();
          try {
              JSONArray serverArray = new JSONArray(doDelete(BASE_SERVERGROUP + "/" + serverGroupId, null));
              for (int i = 0; i < serverArray.length(); i++) {
                  JSONObject jsonServerGroup = serverArray.getJSONObject(i);
                  ServerGroup group = getServerGroupFromJSON(jsonServerGroup);
                  groups.add(group);
              }
          } catch (Exception e) {
              e.printStackTrace();
              return null;
          }
          return groups;
      }
docs: Delete a server group
  
  @param serverGroupId ID of serverGroup
  @return Collection of active Server Groups