code: function(feature, minTime, maxTime) {
          var featureStringTimes = this._getFeatureTimes(feature);
          if (featureStringTimes.length == 0) {
              return feature;
          }
          var featureTimes = [];
          for (var i = 0, l = featureStringTimes.length; i < l; i++) {
              var time = featureStringTimes[i]
              if (typeof time == 'string' || time instanceof String) {
                  time = Date.parse(time.trim());
              }
              featureTimes.push(time);
          }
  
          if (featureTimes[0] > maxTime || featureTimes[l - 1] < minTime) {
              return null;
          }
          return feature;
      }
docs: Do not modify features. Just return the feature if it intersects the time interval