Provide a base class for extendable options.
 /// <summary>
 /// Gets access to the <see cref="DispatchProperties"/> passed to the dispatcher.
 /// </summary>
 public static DispatchProperties GetDispatchProperties(this ExtendableOptions options)
 {
     Guard.AgainstNull(nameof(options), options);
     return(options.DispatchProperties);
 }
 /// <summary>
 /// Gets access to a "bucket" that allows the developer to pass information from extension methods down to behaviors.
 /// </summary>
 public static ContextBag GetExtensions(this ExtendableOptions options)
 {
     Guard.AgainstNull(nameof(options), options);
     return(options.Context);
 }