use base 'Quantum::Superpositions::Conj';

##</code><code>##

    use base qw(Foo Bar);
[...is...]
Roughly similar in effect to

    BEGIN {
        require Foo;
        require Bar;
        push @ISA, qw(Foo Bar);
    }

##</code><code>##

use vars qw($VERSION);
BEGIN { $VERSION= $Quantum::Superpositions::VERSION }