use feature 'switch';
no warnings 'experimental';

$m = 'test';
given ( $m )  {
    when ('test')   {  test::Get() };
}

package test;
sub Get {
    require IO::All;
    $data = io();
}
1;

##</code><code>##

% perl t.pl 
Undefined subroutine &test::io called at t.pl line 11.

##</code><code>##

$data = IO::All::io()

##</code><code>##

Can't call method "_package" on an undefined value at /usr/share/perl5/vendor_perl/IO/All.pm line 63.