p6.p6

class LedgerFromFile {...};
class LedgerFromPkg {...};

class Ledger {
    multi method new(:$file!) { LedgerFromFile.bless: :$file }
    multi method new(:$pkg!)  { LedgerFromPkg .bless: :$pkg  }
}

class LedgerFromFile is Ledger {
    has Str $.file is required;
};
class LedgerFromPkg is Ledger {
    has Str $.pkg is required;
}

Ledger.new(:file<mario>).say;
Ledger.new(:pkg<meow>).say;