use Object::InsideOut qw(class_insideout);

##</code><code>##

  use base qw(class_insideout);

##</code><code>##

Sub-classes (child classes) inherit from base classes (parent classes)
by telling Object::InsideOut what the parent class is:

package My::Sub; {
  use Object::InsideOut qw(My::Parent);
  ...
}
<snip>
Object::InsideOut acts as a replacement for the "base" pragma:  It
loads the parent module(s), calls their "->import()" methods, and sets
up the sub-class's @ISA array.  Therefore, you should not "use base ..." yourself