<PackageReference Include="NETStandard.Library" Version="2.0.3" />

System.ComponentModel.DefaultValueAttribute

namespace System.ComponentModel { public class DefaultValueAttribute : Attribute { public virtual object Value { get; } public DefaultValueAttribute(bool value); public DefaultValueAttribute(byte value); public DefaultValueAttribute(char value); public DefaultValueAttribute(double value); public DefaultValueAttribute(short value); public DefaultValueAttribute(int value); public DefaultValueAttribute(long value); public DefaultValueAttribute(object value); public DefaultValueAttribute(float value); public DefaultValueAttribute(string value); public DefaultValueAttribute(Type type, string value); protected void SetValue(object value); } }