examples/flux-todo-riot/bundle.js
function defineProperty(el, key, value, options) {
  Object.defineProperty(el, key, extend({
    value: value,
    enumerable: false,
    writable: false,
    configurable: true
  }, options));
  return el
}
function defineProperty(el, key, value, options) {
  Object.defineProperty(el, key, extend({
    value: value,
    enumerable: false,
    writable: false,
    configurable: true
  }, options));
  return el
}
function defineProperty ( el , key , value , options ) { Object . defineProperty ( el , key , extend ( { value : value , enumerable : false , writable : false , configurable : true } , options ) ) ; return el }
Helper function to set an immutable property
@param   { Object } el - object where the new property will be set
@param   { String } key - object key where the new property will be stored
@param   { * } value - value of the new property
@param   { Object } options - set the propery overriding the default options
@returns { Object } - the initial object
Helper function to set an immutable property