code: async def addCharm(self, charm, series):
          
          # We don't add local charms because they've already been added
          # by self._handle_local_charms
          if charm.startswith('local:'):
              return charm
  
          entity_id = await self.charmstore.entityId(charm)
          log.debug('Adding %s', entity_id)
          await self.client_facade.AddCharm(None, entity_id)
          return entity_id
docs: :param charm string:
              Charm holds the URL of the charm to be added.
  
          :param series string:
              Series holds the series of the charm to be added
              if the charm default is not sufficient.