Javascript object method with working private and static

jsClass.js

/** METHOD ONE **/
/** DOES NOT WORK WITH instanceof **/
var MyClass = (function ()
{
  /* STATIC */

  // private static
  var _privateStatic = 'static private initial';
  
  // public static
  _class.staticProperty = 'static initial';

  /* NON-STATIC */
  function _class(initialPublic)
  {
    var _privateProperty = 'private initial';

    function __construct()
    {
      console.log('init with', initialPublic);
      this.publicProperty = initialPublic;
    }

    __construct.prototype.getPrivate = function ()
    {
      return _privateProperty;
    };
    __construct.prototype.setPrivate = function (value)
    {
      _privateProperty = value;
    };

    return new __construct();
  }

  return _class;
})();

var p1 = new MyClass('initial test 1');
p1.setPrivate('test1');
var p2 = new MyClass('initial test 2');
p2.setPrivate('test2');
console.log('static', MyClass.staticProperty);
MyClass.staticProperty = 'non-initial';
console.log('p1', p1.getPrivate(), p1.publicProperty, MyClass.staticProperty, p1 instanceof MyClass);
console.log('p2', p2.getPrivate(), p2.publicProperty, MyClass.staticProperty, p2 instanceof MyClass);

/*
OUTPUT:

init with initial test 1
init with initial test 2
static static initial
p1 test1 initial test 1 non-initial false
p2 test2 initial test 2 non-initial false
*/


/** METHOD TWO **/
/** WORKS WITH instanceof, BUT PUBLIC FUNCTION CLOSURES CREATED FOR EACH INSTANCE **/
var MyClass = (function ()
{
  /* PRIVATE STATIC */
  var _privateStatic = 'static private initial';

  /* PUBLIC STATIC */
  _class.staticProperty = 'static initial';

  /* INSTANCE CONSTRUCTOR */
  function _class(initialPublic)
  {
    /* PRIVATE */
    var _privateProperty = 'private initial';

    /* PUBLIC */
    this.getPrivate = function ()
    {
      return _privateProperty;
    };

    this.setPrivate = function (value)
    {
      _privateProperty = value;
    };

    /* CONSTRUCTION CODE */
    console.log('init with', initialPublic);
    this.publicProperty = initialPublic;
  }

  return _class;
})();

var p1 = new MyClass('initial test 1');
p1.setPrivate('test1');
var p2 = new MyClass('initial test 2');
p2.setPrivate('test2');
console.log('static', MyClass.staticProperty);
MyClass.staticProperty = 'non-initial';
console.log('p1', p1.getPrivate(), p1.publicProperty, MyClass.staticProperty, p1 instanceof MyClass);
console.log('p2', p2.getPrivate(), p2.publicProperty, MyClass.staticProperty, p2 instanceof MyClass);

/*
OUTPUT:

init with initial test 1
init with initial test 2
static static initial
p1 test1 initial test 1 non-initial true
p2 test2 initial test 2 non-initial true
*/