public static bool IsDefined <TEnum>(TEnum value) where TEnum : struct, IComparable, IFormattable, IConvertible => Holder <TEnum> .IsDefined(value);
public static bool IsDefined <TEnum>(TEnum value) where TEnum : struct, Enum => Holder <TEnum> .IsDefined(value);
public static bool IsDefined <TEnum>([NotNull] string value) where TEnum : struct, Enum => TryParse <TEnum>(value, out var parsed) && Holder <TEnum> .IsDefined(parsed);
public static bool IsDefined <TEnum>([NotNull] string value) where TEnum : struct, IComparable, IFormattable, IConvertible => TryParse <TEnum>(value, out var parsed) && Holder <TEnum> .IsDefined(parsed);