code: public Set<CmsUser> readResponsibleUsers(CmsDbContext dbc, CmsResource resource) throws CmsException {
  
          Set<CmsUser> result = new HashSet<CmsUser>();
          Iterator<I_CmsPrincipal> principals = readResponsiblePrincipals(dbc, resource).iterator();
          while (principals.hasNext()) {
              I_CmsPrincipal principal = principals.next();
              if (principal.isGroup()) {
                  try {
                      result.addAll(getUsersOfGroup(dbc, principal.getName(), true, false, false));
                  } catch (CmsException e) {
                      if (LOG.isInfoEnabled()) {
                          LOG.info(e);
                      }
                  }
              } else {
                  result.add((CmsUser)principal);
              }
          }
          return result;
      }
docs: Returns the set of users that are responsible for a specific resource.<p>
  
  @param dbc the current database context
  @param resource the resource to get the responsible users from
  
  @return the set of users that are responsible for a specific resource
  
  @throws CmsException if something goes wrong