fs.readFile('data/PGA_2records.mrk', function(err, data) {
    marc4js.parse(data, {fromFormat: 'mrk'}, function(err, records) {
        records.length.should.eql(2);
    });
});
fs.readFile('data/collection.json', function(err, data) {
    marc4js.parse(data, {fromFormat: 'json'}, function(err, records) {
        records.length.should.eql(2);
    });
});
fs.readFile('data/PGA-other-2.mrc', function(err, data) {
    marc4js.parse(data, {}, function(err, records) {
        records.length.should.eql(159);
    });
});