code: function bnpDLShiftTo(n,r) {
    var this_array = this.array;
    var r_array = r.array;
    var i;
    for(i = this.t-1; i >= 0; --i) r_array[i+n] = this_array[i];
    for(i = n-1; i >= 0; --i) r_array[i] = 0;
    r.t = this.t+n;
    r.s = this.s;
  }
docs: (protected) r = this << n*DB