EXAMPLE

 our %item_db = (
    '1565921879' => {
        title => "Perl 5 desktop reference",
        id => '1565921879',
        sip_media_type => '001',
        magnetic_media => 0,
        hold_queue => [],
    },
    '0440242746' => {
        title => "The deep blue alibi",
        id => '0440242746',
        sip_media_type => '001',
        magnetic_media => 0,
        hold_queue => [
            {
            itemnumber => '823',
            priority => '1',
            reservenotes => undef,
            reservedate => '2008-10-09',
            found => undef,
            rtimestamp => '2008-10-09 11:15:06',
            biblionumber => '406',
            borrowernumber => '756',
            branchcode => 'CPL'
            }
        ],
    },
    '660' => {
        title => "Harry Potter y el cáliz de fuego",
        id => '660',
        sip_media_type => '001',
        magnetic_media => 0,
        hold_queue => [],
    },
);