old_contents: """Stop Bins."""
  import util
  import errors
  import registry
  import entities
  
  class StopBin(object):
    def __init__(self, prefix):
      self.prefix = prefix
      self._stops = {}
      
    def stops(self):
      return self._stops.values()
      
    def add_stop(self, stop):
      key = stop.onestop()
      # New stop
      if key not in self._stops:
        self._stops[key] = stop
      else:
        self._stops[key].merge(stop)
  
    @classmethod
    def from_json(cls, data):
      stopbin = cls(prefix=data['prefix'])    
      for feature in data['features']:
        stop = entities.OnestopStop.from_json(feature)
        stopbin.add_stop(stop)
      return stopbin
      
    def json(self):
      return {
        'type': 'FeatureCollection',
        'properties': {},
        'prefix': self.prefix,
        'features': [
          i.json() 
          for i in 
          sorted(self.stops(), key=lambda x:x.onestop())
        ]
      }    
  
new_contents: """Stop Bins."""
  import util
  import errors
  import registry
  import entities
  
  class StopBin(object):
    def __init__(self, prefix):
      self.prefix = prefix
      self._stops = {}
      
    def stops(self):
      return self._stops.values()
      
    def add_stop(self, stop):
      key = stop.onestop()
      # New stop
      if key not in self._stops:
        self._stops[key] = stop
      else:
        self._stops[key].merge(stop)
      return self._stops[key]
  
    @classmethod
    def from_json(cls, data):
      stopbin = cls(prefix=data['prefix'])    
      for feature in data['features']:
        stop = entities.OnestopStop.from_json(feature)
        stopbin.add_stop(stop)
      return stopbin
      
    def json(self):
      return {
        'type': 'FeatureCollection',
        'properties': {},
        'prefix': self.prefix,
        'features': [
          i.json() 
          for i in 
          sorted(self.stops(), key=lambda x:x.onestop())
        ]
      }    
  
subject: Return added stop in StopBin.add_stop()