dump method
Creates a readable dump from the current ASN1Object.
Important note: Subclasses need to override this method. If the ASN1Object is constructed and has child elements, dump() has to be called for each child element.
Implementation
@override
String dump({int spaces = 0}) {
var sb = StringBuffer();
for (var i = 0; i < spaces; i++) {
sb.write(' ');
}
sb.write('NULL');
return sb.toString();
}