      }
      
      this.fragments.filter(this.currentEnterFragments.bind(this)).forEach(this.showFragment);
      this.fragments.filter(this.currentExitFragments.bind(this)).forEach(this.hideFragment);
      this.currentStep++;
      return true;
    };
    
    FragmentsController.prototype.previous = function() {
      if(this.currentStep === 0 || this.currentStep > this.steps.length) {
        return false;
      }
      
      this.currentStep--;
      this.fragments.filter(this.currentEnterFragments.