$hshFoo{$keyNew} = $strFile;
# Ex:
#        $hshFoo{"203000"} = "203000.xml";

##</code><code>##

#######################
# here is the code...
sub get_hshAgg {
    my $self = shift;
    return %{$self->{hshAgg}};
}

sub set_hshAgg {
    my $self = shift;
    my %hshToAgg = shift;

    $self->{hshAgg} = \%hshToAgg;
}

sub run {
    my $self        = Foo->new(@_);
    my %hshToAgg      = ();

    my $class;

    (
     $class,
     %hshToAgg
    ) = @_;

    $self->set_id($intID);
    $self->set_hshAgg(%hshToAgg);

    use Data::Dumper;
    print Dumper \%hshToAgg;

    # OUTPUT: THIS WORKS! 
    #$VAR1 = {
    #          '2030000' => '2030000.XML',
    #          '2030001' => '2030001.XML',
    #          '2030002' => '2030002.XML'
    #        };

    print "After instantiation\n");
    my %hshTest = $self->get_hshAgg();
    print Dumper \%hshTest;

    # OUTPUT: THIS DOES NOT WORK! 
    #$VAR1 = {
    #          '2030000' => undef
    #        };
}