function at( x, index ) {
	var get;
	if ( hasMethod( x, 'at' ) ) {
		return x.at( index );
	}
	if ( index < 0 ) {
		index += x.length;
		if ( index < 0 ) {
			return;
		}
	} else if ( index >= x.length ) {
		return;
	}
	get = resolveGetter( x );
	return get( x, index );
}
Returns an element from an array.

@param {Collection} x - input array
@param {integer} index - element index
@returns {*} array element

@example
var x = [ 1, 2, 3, 4 ];

var v = at( x, 0 );
// returns 1

v = at( x, 1 );
// returns 2

v = at( x, -2 );
// returns 3