/// <summary>
 /// Constructor.
 /// </summary>
 /// <param name="serviceContext">An <see cref="OrganizationServiceContext"/>.</param>
 /// <param name="securityProvider">An <see cref="ICrmEntitySecurityProvider"/>.</param>
 /// <param name="httpContext">An <see cref="HttpContextBase"/>.</param>
 /// <param name="portalContext">An <see cref="IPortalContext"/> to get user and website <see cref="EntityReference"/>s from.</param>
 public DataAdapterDependencies(OrganizationServiceContext serviceContext, ICrmEntitySecurityProvider securityProvider,
                                HttpContextBase httpContext, IPortalContext portalContext, RequestContext requestContext = null)
     : this(
         serviceContext,
         securityProvider,
         httpContext,
         portalContext.Website == null ? null : portalContext.Website.ToEntityReference(),
         portalContext.User != null ? portalContext.User.ToEntityReference() : null,
         requestContext : requestContext)
 {
     portalContext.ThrowOnNull("portalContext");
 }