old_contents: var _ = require('underscore');
  var BackbonePoller = require('backbone-poller');
  
  var AnalysisPoller = function () {
    this._pollers = [];
  };
  
  AnalysisPoller.CONFIG = {
    START_DELAY: 1000,
    MAX_DELAY: Infinity,
    DELAY_MULTIPLIER: 1.5
  };
  
  AnalysisPoller.prototype.resetAnalysisNodes = function (analysisModels) {
    this.reset();
    _.each(analysisModels, function (analysisModel) {
      this._poll(analysisModel);
    }, this);
  };
  
  AnalysisPoller.prototype._poll = function (analysisModel) {
    if (this._canBePolled(analysisModel)) {
      var poller = this._createPoller(analysisModel);
      poller.start();
    }
  };
  
  AnalysisPoller.prototype._canBePolled = function (analysisModel) {
    return analysisModel.url() && !analysisModel.isDone();
  };
  
  AnalysisPoller.prototype._findPoller = function (analysisModel) {
    return _.find(this._pollers, function (poller) {
      return poller.model === analysisModel;
    });
  };
  
  AnalysisPoller.prototype._createPoller = function (analysisModel) {
    var pollerOptions = {
      delay: [
        AnalysisPoller.CONFIG.START_DELAY,
        AnalysisPoller.CONFIG.MAX_DELAY,
        AnalysisPoller.CONFIG.DELAY_MULTIPLIER
      ],
      condition: function (analysisModel) {
        return !analysisModel.isDone();
      }
    };
  
    var poller = BackbonePoller.get(analysisModel, pollerOptions);
    this._pollers.push(poller);
    return poller;
  };
  
  AnalysisPoller.prototype.reset = function () {
    BackbonePoller.reset();
    this._pollers = [];
  };
  
  module.exports = AnalysisPoller;
  
new_contents: var _ = require('underscore');
  var BackbonePoller = require('backbone-poller');
  
  function AnalysisPoller () {
    this._pollers = [];
  }
  
  AnalysisPoller.CONFIG = {
    START_DELAY: 1000,
    MAX_DELAY: Infinity,
    DELAY_MULTIPLIER: 1.5
  };
  
  AnalysisPoller.prototype.resetAnalysisNodes = function (analysisModels) {
    this.reset();
    _.each(analysisModels, function (analysisModel) {
      this._poll(analysisModel);
    }, this);
  };
  
  AnalysisPoller.prototype._poll = function (analysisModel) {
    if (this._canBePolled(analysisModel)) {
      var poller = this._createPoller(analysisModel);
      poller.start();
    }
  };
  
  AnalysisPoller.prototype._canBePolled = function (analysisModel) {
    return analysisModel.url() && !analysisModel.isDone();
  };
  
  AnalysisPoller.prototype._findPoller = function (analysisModel) {
    return _.find(this._pollers, function (poller) {
      return poller.model === analysisModel;
    });
  };
  
  AnalysisPoller.prototype._createPoller = function (analysisModel) {
    var pollerOptions = {
      delay: [
        AnalysisPoller.CONFIG.START_DELAY,
        AnalysisPoller.CONFIG.MAX_DELAY,
        AnalysisPoller.CONFIG.DELAY_MULTIPLIER
      ],
      condition: function (analysisModel) {
        return !analysisModel.isDone();
      }
    };
  
    var poller = BackbonePoller.get(analysisModel, pollerOptions);
    this._pollers.push(poller);
    return poller;
  };
  
  AnalysisPoller.prototype.reset = function () {
    BackbonePoller.reset();
    this._pollers = [];
  };
  
  module.exports = AnalysisPoller;
  
subject: Use funcion declaration