package ParentModule;
use strict;

sub base_foo {};
sub base_baz {};

sub import {
    my ($class,@routines) = @_;
    my $target = caller;

    # Install the requested routines in the target package
    for my $name (@routines) {
        no strict 'refs';
        *{"$target\::$name"} = \&{"base_$name"};
    };
};

1;

##</code><code>##

package ChildModule1;
use strict;
use ParentModule qw( foo bar );

package ChildModule2;
use strict;
use ParentModule qw( foo );

# Own implementation of bar()
sub bar {...};

1;