code: def embed(self, url, **kwargs):
          
          try:
              # first figure out the provider
              provider = self.provider_for_url(url)
          except OEmbedMissingEndpoint:
              raise
          else:
              try:
                  # check the database for a cached response, because of certain
                  # race conditions that exist with get_or_create(), do a filter
                  # lookup and just grab the first item
                  stored_match = StoredOEmbed.objects.filter(
                      match=url, 
                      maxwidth=kwargs.get('maxwidth', None), 
                      maxheight=kwargs.get('maxheight', None),
                      date_expires__gte=datetime.datetime.now())[0]
                  return OEmbedResource.create_json(stored_match.response_json)
              except IndexError:
                  # query the endpoint and cache response in db
                  # prevent None from being passed in as a GET param
                  params = dict([(k, v) for k, v in kwargs.items() if v])
                  
                  # request an oembed resource for the url
                  resource = provider.request_resource(url, **params)
                  
                  try:
                      cache_age = int(resource.cache_age)
                      if cache_age < MIN_OEMBED_TTL:
                          cache_age = MIN_OEMBED_TTL
                  except:
                      cache_age = DEFAULT_OEMBED_TTL
                  
                  date_expires = datetime.datetime.now() + datetime.timedelta(seconds=cache_age)
                  
                  stored_oembed, created = StoredOEmbed.objects.get_or_create(
                      match=url,
                      maxwidth=kwargs.get('maxwidth', None),
                      maxheight=kwargs.get('maxheight', None))
                  
                  stored_oembed.response_json = resource.json
                  stored_oembed.resource_type = resource.type
                  stored_oembed.date_expires = date_expires
                  
                  if resource.content_object:
                      stored_oembed.content_object = resource.content_object
                  
                  stored_oembed.save()
                  return resource
docs: The heart of the matter