sub new {
      my $proto=shift;
      my $class=ref $proto || $proto;
      my $self={ @_ };

      ## ...
      
      bless $self,$class;
   }

##</code><code>##

    my $inst=new MyClass(
                 name => 'mr.nick',
                 rank => 'novice',
                 sleep_level => 'not enough'
             );