use strict;
use warnings;

##</code><code>##

sub TIEHASH {
   print "<@_ \n>";
   my $class = shift;
   my %hash = shift; # <-- you create a hash with a single key, no value. You want @_.
   print "In TIEHASH .... \n";
   return bless(\@hash); # <-- the ARRAY @hash does not exist. You want %hash.
}