docs: private boolean fixupACL(List<Id> authInfo, List<ACL> acl) {
          if (skipACL) {
              return true;
          }
          if (acl == null || acl.size() == 0) {
              return false;
          }
          Iterator<ACL> it = acl.iterator();
          LinkedList<ACL> toAdd = null;
          while (it.hasNext()) {
              ACL a = it.next();
              Id id = a.getId();
              if (id.getScheme().equals("world") && id.getId().equals("anyone")) {
                  // wide open
              } else if (id.getScheme().equals("auth")) {
                  // This is the "auth" id, so we have to expand it to the
                  // authenticated ids of the requestor
                  it.remove();
                  if (toAdd == null) {
                      toAdd = new LinkedList<ACL>();
                  }
                  boolean authIdValid = false;
                  for (Id cid : authInfo) {
                      AuthenticationProvider ap = ProviderRegistry
                              .getProvider(cid.getScheme());
                      if (ap == null) {
                          LOG.error("Missing AuthenticationProvider for "
                                  + cid.getScheme());
                      } else if (ap.isAuthenticated()) {
                          authIdValid = true;
                          toAdd.add(new ACL(a.getPerms(), cid));
                      }
                  }
                  if (!authIdValid) {
                      return false;
                  }
              } else {
                  AuthenticationProvider ap = ProviderRegistry.getProvider(id
                          .getScheme());
                  if (ap == null) {
                      return false;
                  }
                  if (!ap.isValid(id.getId())) {
                      return false;
                  }
              }
          }
          if (toAdd != null) {
              for (ACL a : toAdd) {
                  acl.add(a);
              }
          }
          return acl.size() > 0;
      }