How can I invoke method in CircuitHandler of Blazor server-side?

This should be working, I guess ;)

CircuitHandlerService.cs

using Microsoft.AspNetCore.Components.Server.Circuits;
using System;
using System.Collections.Concurrent;
using System.Threading;
using System.Threading.Tasks;


namespace BlazorCircuitHandler.Services
{
    public class CircuitHandlerService : CircuitHandler
    {
        public ConcurrentDictionary<string, Circuit> Circuits { get; 
            set; }
        public event EventHandler CircuitsChanged;

        protected virtual void OnCircuitsChanged()
             => CircuitsChanged?.Invoke(this, EventArgs.Empty);

        public CircuitHandlerService()
        {
             Circuits = new ConcurrentDictionary<string, Circuit>();
        }

        public override Task OnCircuitOpenedAsync(Circuit circuit, 
                             CancellationToken cancellationToken)
       {
             Circuits[circuit.Id] = circuit;
             OnCircuitsChanged();
             return base.OnCircuitOpenedAsync(circuit, 
                                   cancellationToken);
       }

       public override Task OnCircuitClosedAsync(Circuit circuit, 
                 CancellationToken cancellationToken)
      {
           Circuit circuitRemoved;
           Circuits.TryRemove(circuit.Id, out circuitRemoved);
           OnCircuitsChanged();
           return base.OnCircuitClosedAsync(circuit, 
                             cancellationToken);
      }

      public override Task OnConnectionDownAsync(Circuit circuit, 
                            CancellationToken cancellationToken)
      {
          return base.OnConnectionDownAsync(circuit, 
                           cancellationToken);
      }

      public override Task OnConnectionUpAsync(Circuit circuit, 
                          CancellationToken cancellationToken)
      {
          return base.OnConnectionUpAsync(circuit, cancellationToken);
      }
   }
 }

Usage

@page "/"

@using Microsoft.AspNetCore.Components.Server.Circuits
@using BlazorCircuitHandler.Services

@inject CircuitHandler circuitHandler
@implements IDisposable



<h1>Hello, world!</h1>

Welcome to your new app.

<p>
 Number of Circuits: @((circuitHandler as 
 BlazorCircuitHandler.Services.CircuitHandlerService).Circuits.Count)
 <ul>
    @foreach (var circuit in (circuitHandler as 
     BlazorCircuitHandler.Services.CircuitHandlerService).Circuits)
    {
        <li>@circuit.Key</li>
    }
 </ul>
</p>

@code {
   protected override void OnInitialized()
   {
       // Subscribe to the event handler
    (circuitHandler as CircuitHandlerService).CircuitsChanged += 
         HandleCircuitsChanged;

    }

 public void Dispose()
 {
    // Unsubscribe the event handler when the component is disposed
    (circuitHandler as CircuitHandlerService).CircuitsChanged -= 
      HandleCircuitsChanged;

 }

 public void HandleCircuitsChanged(object sender, EventArgs args)
 {
    // notify the component that its state has changed 
    // Important: You must use InvokeAsync
    InvokeAsync(() => StateHasChanged());
 }
}

Note: To verify that it is working run the app. Then open another two tabs. Now, close the first tab you open (left to right), then the second. Notice the display of the number of active circuits...