spectre.console/src/Spectre.Console/Prompts/ISelectionItem.cs

namespace Spectre.Console
{
    /// <summary>
    /// Represent a selection item.
    /// </summary>
    /// <typeparam name="T">The data type.</typeparam>
    public interface ISelectionItem<T>
        where T : notnull
    {
        /// <summary>
        /// Adds a child to the item.
        /// </summary>
        /// <param name="child">The child to add.</param>
        /// <returns>A new <see cref="ISelectionItem{T}"/> instance representing the child.</returns>
        ISelectionItem<T> AddChild(T child);
    }
}