public string ToPrettyString()
{
return("ModuleItemSequenceNode {" +
($"\n{nameof(Prev)}: {Prev?.ToPrettyString()}," +
$"\n{nameof(Current)}: {Current?.ToPrettyString()}," +
$"\n{nameof(Next)}: {Next?.ToPrettyString()}," +
$"\n{nameof(MasteryPath)}: {MasteryPath?.ToString(Formatting.Indented)}").Indent(4) +
"\n}");
}