sub one {
    my ($self, $value) = @_;
    
    $self->{one} = $value if defined $value;
    return $self->{one} // 1;
}
sub two {
    my ($self, $value) = @_;
    
    $self->{two} = $value if defined $value;
    return $self->{two} // 2;
}
# and so on...