private TeamFoundationIdentity ADSearchAssistResolveIdentityInternal(
            string id,
            MembershipQuery queryMembership,
            ReadIdentityOptions readIdentityOptions)
        {
            /*
             * obsoleting the usage of m_userIdCache to by-pass the TFS user idenitity scalability issue
             *
             * if (null == m_userIdCache)
             * {
             *  return null;
             * }
             * string accountName = m_userIdCache.FindAccountName(id);
             *
             */
            string accountName = ADUserSearcher.GetAccountName(id);

            if (string.IsNullOrEmpty(accountName))
            {
                return(null);
            }
            else
            {
                return(m_identityManagement.ReadIdentity(IdentitySearchFactor.AccountName, accountName, queryMembership, readIdentityOptions));
            }
        }
        internal bool TryLookup(
            RichIdentity richIdentity,
            IdentityLookupContext context)
        {
            try
            {
                if (!string.IsNullOrEmpty(richIdentity.DisplayName))
                {
                    if (!m_adSearchOnly)
                    {
                        // "Jeff Smith"
                        TeamFoundationIdentity id = ResolveIdentity(richIdentity.DisplayName,
                                                                    MembershipQuery.None,
                                                                    ReadIdentityOptions.None,
                                                                    IdentitySearchFactor.DisplayName);

                        UpdateRichIdentity(richIdentity, id);
                        return(true);
                    }
                    else
                    {
                        return(ADUserSearcher.TryUpdateAccountDetails(richIdentity.DisplayName, richIdentity));
                    }
                }
                else if (!string.IsNullOrEmpty(richIdentity.Alias) && !string.IsNullOrEmpty(richIdentity.Domain))
                {
                    if (!m_adSearchOnly)
                    {
                        // "Fabrikam\jeffsmith"
                        string accountName        = richIdentity.Domain + @"\" + richIdentity.Alias;
                        TeamFoundationIdentity id = ResolveIdentity(accountName,
                                                                    MembershipQuery.None,
                                                                    ReadIdentityOptions.None,
                                                                    IdentitySearchFactor.AccountName);
                        UpdateRichIdentity(richIdentity, id);
                        return(true);
                    }
                }
                else if (!string.IsNullOrEmpty(richIdentity.Alias))
                {
                    if (!m_adSearchOnly)
                    {
                        TeamFoundationIdentity id = ResolveIdentity(richIdentity.Alias,
                                                                    MembershipQuery.None,
                                                                    ReadIdentityOptions.None,
                                                                    IdentitySearchFactor.AccountName);
                        UpdateRichIdentity(richIdentity, id);
                        return(true);
                    }
                }

                return(false);
            }
            catch (IdentityUnresolvedException unrslvEx)
            {
                TraceManager.TraceInformation(unrslvEx.Message);
                return(false);
            }
            catch (IllegalIdentityException illglIdEx)
            {
                TraceManager.TraceInformation(illglIdEx.Message);
                return(false);
            }
        }