API Sisk.Core.Entity HttpHeaderCollection Copy page Copy as Markdown View as Markdown Copy linkPropertyHttpHeaderCollection.IfModifiedSinceNamespaceSisk.Core.EntityAssemblySisk.Core.dllIfModifiedSince #Gets the value of the HTTP If-Modified-Since header.Used to make a conditional request, allowing the client to specify that the resource should only be returned if it has been modified since the given date.C# public string? IfModifiedSince { get; }Property Value #string?