{
    _id:ObjectId('bca678b67a68b76ca'),
    username:'Pepito',
    password:'C0nT_4SeN-@!;',
    files:
        [

            {
                name:'Hoja 1',
                cols:15,
                rows:12,
                cells:
                    [
                        {
                            row:1,
                            column:65,
                            value:1
                        },
                        ...
                    ]
            },
            ...
        ]
}