docs: function() {
  			var arg = arguments;
  			var idx = arg[0];
  			var add = convert(this, [].slice.call(arg, 2));
  			var fix = [idx, arg[1]].concat(add);
  			var out = proto.splice.apply(this, fix);
  			if (observes(this)) {
  				onchange(this, idx, out, add);
  			}
  			return out;
  		}