$method //= '';

##</code><code>##

$method = '' if ! defined $method;

##</code><code>##

defined_or( $method, '' );

# changes the caller's variable
sub defined_or {
    if ( ! defined $_[0] ) {
        $_[0] = $_[1];
    }
}

##</code><code>##

no warnings 'uninitialized';