class Dog {
    has Str $.name;

    method bark($dog: Int:D $x) {
        say $dog.^name;   # $dog is an explicit variable that refers to the invocant
        say $dog.name;
        say "bark" for 1..$x;       
    }
}

my $d = Dog.new(name => "Rover");
$d.bark(3);

--output:--
Dog
Rover
bark
bark
bark