function hasGetterOrSetter(def){ 
return (!!def.get && typeof def.get === 'function') || (!!def.set && typeof def.set === 'function'); 
} 
function getProperty(definition, k, isClassDescriptor){ 
var def = (isClassDescriptor)? definition[k]: Object.getOwnPropertyDescriptor(definition, k); 
if (!isClassDescriptor && def.value && typeof def.value === 'object') { 
def = def.value; 
} 
if (def && hasGetterOrSetter(def)) { 
if (typeof def.enumerable === 'undefined') { 
def.enumerable = true ; 
} 
if (typeof def.configurable === 'undefined') { 
def.configurable = true ; 
} 
return def; 
} 
 else { 
return false ; 
} 
} 
function hasNonConfigurable(obj, k){ 
var prop = Object.getOwnPropertyDescriptor(obj, k); 
if (!prop) { 
return false ; 
} 
if (prop.value && typeof prop.value === 'object') { 
prop = prop.value; 
} 
if (prop.configurable === false ) { 
return true ; 
} 
return false ; 
} 
function extend(ctor, definition, isClassDescriptor, extend){ 
for (var k in definition){ 
if (!definition.hasOwnProperty(k)) { 
continue ; 
} 
var def = getProperty(definition, k, isClassDescriptor); 
if (def !== false ) { 
var parent = extend || ctor; 
if (hasNonConfigurable(parent.prototype, k)) { 
if (Class.ignoreFinals) { 
continue ; 
} 
throw new Error('cannot override final property \'' + k + '\', set Class.ignoreFinals = true to skip')
} 
Object.defineProperty(ctor.prototype, k, def); 
} 
 else { 
ctor.prototype[k] = definition[k]; 
} 
} 
} 
function mixin(myClass, mixins){ 
if (!mixins) { 
return ; 
} 
if (!Array.isArray(mixins)) { 
mixins = [mixins] ; 
} 
for (var i = 0; 
i < _AN_Read_length('length', mixins); i++ ){ 
extend(myClass, mixins[i].prototype || mixins[i]); 
} 
} 
function Class(definition){ 
if (!definition) { 
definition = { 
}
; 
} 
var initialize; 
var Extends; 
if (definition.initialize) { 
if (typeof definition.initialize !== 'function') { 
throw new Error('initialize must be a function')
} 
initialize = definition.initialize; 
delete definition.initialize; 
} 
 else if (definition.Extends) { 
var base = definition.Extends; 
initialize = function (){ 
base.apply(this, arguments); 
} 
; 
} 
 else { 
initialize = function (){ 
} 
; 
} 
if (definition.Extends) { 
initialize.prototype = Object.create(definition.Extends.prototype); 
initialize.prototype.constructor = initialize; 
Extends = definition.Extends; 
delete definition.Extends; 
} 
 else { 
initialize.prototype.constructor = initialize; 
} 
var mixins = null ; 
if (definition.Mixins) { 
mixins = definition.Mixins; 
delete definition.Mixins; 
} 
mixin(initialize, mixins); 
extend(initialize, definition, true , Extends); 
return initialize; 
} 
Class.extend = extend; 
Class.mixin = mixin; 
Class.ignoreFinals = false ; 
module.exports = Class;