public static bool IsRequiredReference(this ContextualTypeModelClassification flags) => flags.HasFlag(ContextualTypeModelClassification.ReferenceType | ContextualTypeModelClassification.Required);
public static bool IsOptionalReference(this ContextualTypeModelClassification flags) => flags.HasFlag(ContextualTypeModelClassification.ReferenceType | ContextualTypeModelClassification.Optional);
public static bool IsOptionalValue(this ContextualTypeModelClassification flags) => flags.HasFlag(ContextualTypeModelClassification.ValueType | ContextualTypeModelClassification.Optional);