code: function File(chunks, name, opts) {
        opts = opts || {}
        var a = Blob.call(this, chunks, opts) || this
        a.name = name
        a.lastModifiedDate = opts.lastModified ? new Date(opts.lastModified) : new Date
        a.lastModified = +a.lastModifiedDate
        
        return a
      }
docs: ***************************************************** /*                   File constructor *****************************************************