index.js
function setup (index) {
  function get () {
    return this[ArrayIndex.get](index);
  }
  function set (v) {
    return this[ArrayIndex.set](index, v);
  }
  return {
    enumerable: true,
    configurable: true,
    get: get,
    set: set
  };
}
function setup (index) {
  function get () {
    return this[ArrayIndex.get](index);
  }
  function set (v) {
    return this[ArrayIndex.set](index, v);
  }
  return {
    enumerable: true,
    configurable: true,
    get: get,
    set: set
  };
}
function setup ( index ) { function get ( ) { return this [ ArrayIndex . get ] ( index ) ; } function set ( v ) { return this [ ArrayIndex . set ] ( index , v ) ; } return { enumerable : true , configurable : true , get : get , set : set } ; }
Returns a property descriptor for the given "index", with "get" and "set"
functions created within the closure.

@api private
Returns a property descriptor for the given index with get and set functions created within the closure .