old_contents: import json
  import aiohttp
  
  
  class EventsServiceAPIError(Exception):
      def __init__(self, errors=None):
          if not errors:
              errors = []
          super().__init__()
          self.errors = errors
  
      def __str__(self):
          return '; '.join(self.errors)
  
  
  class EventsServiceAPI:
      def __init__(self, url):
          self.url = url
          self.session = aiohttp.ClientSession()
  
      async def get_events(self, api_key, offset=0, count=10, sorting=None, query=None):
          if not sorting:
              sorting = ''
          if not query:
              query = ''
          params = {'count': count,
                    'offset': offset,
                    'order_by': sorting,
                    'query': query}
          url = '{}/events'.format(self.url, count, offset, sorting, query)
          async with self.session.get(url,
                                      headers={'Client-Key': api_key},
                                      params=params) as response:
              await self.process_errors(url, response)
              data = await response.json()
          data['events'] = [self.prepare_event(event) for event in data.pop('events')]
          return data
  
      async def get_event(self, api_key, id_):
          url = '{}/events/{}'.format(self.url, id_)
          async with self.session.get(url,
                                      headers={'Client-Key': api_key}) as response:
              await self.process_errors(url, response)
              data = await response.json()
          return self.prepare_event(data)
  
      async def process_errors(self, url, response):
          if response.status > 299:
              if response.status == 400:
                  json = await response.json()
                  raise EventsServiceAPIError(['{}: {} [api]'.format(k, v) for k, v in json.items()])
              raise EventsServiceAPIError(
                  ['Events Service returned {} error by url {}'.format(response.status, url)]
              )
  
      def prepare_event(self, event):
          event['metainfo'] = json.loads(event.pop('metainfo'))
          return event
  
new_contents: import json
  import aiohttp
  
  
  class EventsServiceAPIError(Exception):
      def __init__(self, errors=None):
          if not errors:
              errors = []
          super().__init__()
          self.errors = errors
  
      def __str__(self):
          return '; '.join(self.errors)
  
  
  class EventsServiceAPI:
      def __init__(self, url):
          self.url = url
          self.session = aiohttp.ClientSession()
  
      async def get_events(self, api_key, offset=0, count=10, sorting=None, query=None):
          if not sorting:
              sorting = ''
          if not query:
              query = ''
          params = {'count': count,
                    'offset': offset,
                    'order_by': sorting,
                    'query': query}
          url = '{}/events/'.format(self.url, count, offset, sorting, query)
          async with self.session.get(url,
                                      headers={'Client-Key': api_key},
                                      params=params) as response:
              await self.process_errors(url, response)
              data = await response.json()
          data['events'] = [self.prepare_event(event) for event in data.pop('events')]
          return data
  
      async def get_event(self, api_key, id_):
          url = '{}/events/{}'.format(self.url, id_)
          async with self.session.get(url,
                                      headers={'Client-Key': api_key}) as response:
              await self.process_errors(url, response)
              data = await response.json()
          return self.prepare_event(data)
  
      async def process_errors(self, url, response):
          if response.status > 299:
              if response.status == 400:
                  json = await response.json()
                  raise EventsServiceAPIError(['{}: {} [api]'.format(k, v) for k, v in json.items()])
              raise EventsServiceAPIError(
                  ['Events Service returned {} error by url {}'.format(response.status, url)]
              )
  
      def prepare_event(self, event):
          event['metainfo'] = json.loads(event.pop('metainfo'))
          return event
  
subject: fix url