Custom context class for communicating from parent to child tag helper

HandTagHelper.cs

public class HandContext
{
    public string Player { get; set; }
}

[HtmlTargetElement(Constants.HAND_TAG_HELPER_ELEMENT_NAME, Attributes = nameof(Player), TagStructure = TagStructure.NormalOrSelfClosing)]
[RestrictChildren(Constants.CARD_TAG_HELPER_ELEMENT_NAME)]
public class HandTagHelper : TagHelper
{
    public string Player { get; set; }

    public override void Process(TagHelperContext context, TagHelperOutput output)
    {
        // Assign the lowercase version of the player's name to the appropriate context property
        var handContext = new HandContext
        {
            Player = Player?.Trim().ToLower()
        };
        context.Items.Add(typeof(HandTagHelper), handContext);

        output.TagName = "div";
        output.Attributes.SetAttribute("class", "row");
    }
}