code: function ActionInterval (opts) {
      ActionInterval.superclass.constructor.apply(this, arguments)
  
      var dur = opts.duration || 0
      if (dur === 0) {
          dur = 0.0000001
      }
  
      this.duration = dur
      this.elapsed = 0
      this._firstTick = true
  }
docs: @class
  Base class actions that do have a finite time duration.
  
  Possible actions:
  
  - An action with a duration of 0 seconds
  - An action with a duration of 35.5 seconds Infinite time actions are valid
  
  @memberOf cocos.actions
  @extends cocos.actions.FiniteTimeAction
  
  @opt {Float} duration Number of seconds to run action for