IsVisibleInDynamoLibraryAttribute
This attribute is used to specify whether the item will be displayed
            in the library.
            
using System;
namespace Autodesk.DesignScript.Runtime
{
    [AttributeUsage(AttributeTargets.All, AllowMultiple = false)]
    public sealed class IsVisibleInDynamoLibraryAttribute : Attribute
    {
        public bool Visible { get; set; }
        public IsVisibleInDynamoLibraryAttribute(bool visible)
        {
            Visible = visible;
        }
    }
}
            