code: public Group createGroup(Group group, AccessToken accessToken) {
          return getGroupService().createGroup(group, accessToken);
      }
docs: saves the given {@link Group} to the OSIAM DB.
  
  @param group       group to be saved
  @param accessToken the OSIAM access token from for the current session
  @return the same group Object like the given but with filled metadata and a new valid id
  @throws UnauthorizedException             if the request could not be authorized.
  @throws ConflictException                 if the Group could not be created
  @throws ForbiddenException                if the scope doesn't allow this request
  @throws ConnectionInitializationException if the connection to the given OSIAM service could not be initialized
  @throws IllegalStateException             if OSIAM's endpoint(s) are not properly configured