p6.p6

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

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

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

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