docs: function sectorify(file, ssz) {
  	var nsectors = Math.ceil(file.length/ssz)-1;
  	var sectors = new Array(nsectors);
  	for(var i=1; i < nsectors; ++i) sectors[i-1] = file.slice(i*ssz,(i+1)*ssz);
  	sectors[nsectors-1] = file.slice(nsectors*ssz);
  	return sectors;
  }