code: public void removeUserFromGroup(String username, String groupname) throws CmsException {
  
          m_securityManager.removeUserFromGroup(m_context, username, groupname, false);
      }
docs: Removes a user from a group.<p>
  
  @param username the name of the user that is to be removed from the group
  @param groupname the name of the group
  
  @throws CmsException if operation was not successful