Check out this code listing from Conway's OO Perl. As you will see, he creates encapsulated class data within the class and uses it to help set default values for the object if data is not passed to the consturctor argument. Pick up the book if you haven't already.

$PM = "Perl Monk's";
$MCF = "Most Clueless Friar Abbot Bishop";
$nysus = $PM . $MCF;
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