Panels/UITests/BaseTestPanel.razor
@using Sandbox
@using Sandbox.UI
@namespace Sandbox.UI.Tests.Basics
@inherits Panel

<root>

    <div class="header">
        <label class="title">@Title</label>
        <label class="subtitle">@Subtitle</label>
    </div>

    <div class="body">
        @Body
    </div>

</root>

@code {
    public virtual string Title { get; set; } = "Title";
    public virtual string Subtitle { get; set; } = "Subtitle";

    [Parameter]
    public RenderFragment Body { get; set; }
}