<PackageReference Include="NJsonSchema.Annotations" Version="11.3.2" />

System.Runtime.CompilerServices.CompilerFeatureRequiredAttribute

Indicates that compiler support for a particular feature is required for the location where this attribute is applied.
namespace System.Runtime.CompilerServices { internal sealed class CompilerFeatureRequiredAttribute : Attribute { public const string RefStructs = "RefStructs"; public const string RequiredMembers = "RequiredMembers"; public string FeatureName { get; } public bool IsOptional { get; set; } public CompilerFeatureRequiredAttribute(string featureName); } }