// Taken from: https://github.com/paulmillr/es6-shim/
  
  'use strict';
  
  var toInteger  = require('../../../number/to-integer')
    , toPosInt   = require('../../../number/to-pos-integer')
    , validValue = require('../../../object/valid-value')
  
    , hasOwnProperty = Object.prototype.hasOwnProperty
    , max = Math.max, min = Math.min;
  
  module.exports = function (target, start/*, end*/) {
  	var o = validValue(this), end = arguments[2], l = toPosInt(o.length)
  	  , to, from, fin, count, direction;
  
  	target = toInteger(target);
  	start = toInteger(start);
  	end = (end === undefined) ? l : toInteger(end);
  
  	to = target < 0 ? max(l + target, 0) : min(target, l);
  	from = start < 0 ? max(l + start, 0) : min(start, l);
  	fin = end < 0 ? max(l + end, 0) : min(end, l);
  	count = min(fin - from, l - to);
  	direction = 1;
  
  	if ((from < to) && (to < (from + count))) {
  		direction = -1;
  		from += count - 1;
  		to += count - 1;
  	}
  	while (count > 0) {
  		if (hasOwnProperty.call(o, from)) o[to] = o[from];
  		else delete o[from];
  		from += direction;
  		to += direction;
  		count -= 1;
  	}
  	return o;
  };