docs: function del(/* key-1, key-N, req */) {
    var args = slice.call(arguments, 0)
      , req = typeof args[args.length-1] === 'object' ? args.pop() : null;
    var deleted = 0;
    for(var i = 0;i < args.length;i++) {
      if(this.keyExists(args[i])) {
        this.delKey(args[i], req);
        deleted++;
      }
    }
    return deleted;
  }