DynamoVisualProgramming.DynamoServices by Autodesk

<PackageReference Include="DynamoVisualProgramming.DynamoServices" Version="2.0.4.11375" />

 DefaultArgumentAttribute

public sealed class DefaultArgumentAttribute : Attribute
This attribute can be applied to parameter to specify a default argument expressions.
using System; namespace Autodesk.DesignScript.Runtime { [AttributeUsage(AttributeTargets.Parameter, AllowMultiple = false)] public sealed class DefaultArgumentAttribute : Attribute { public string ArgumentExpression { get; set; } public DefaultArgumentAttribute(string defaultArgumentExpression) { ArgumentExpression = defaultArgumentExpression; } } }