code: def add(self, item):
          '''Add *item* to collection.
  
          raise :py:class:`~clique.error.CollectionError` if *item* cannot be
          added to the collection.
  
          '''
          match = self.match(item)
          if match is None:
              raise clique.error.CollectionError(
                  'Item does not match collection expression.'
              )
  
          self.indexes.add(int(match.group('index'))f add(self, item):
          '''Add *item* to collection.
  
          raise :py:class:`~clique.error.CollectionError` if *item* cannot be
          added to the collection.
  
          '''
          match = self.match(item)
          if match is None:
              raise clique.error.CollectionError(
                  'Item does not match collection expression.'
              )
  
          self.indexes.add(int(match.group('index')))
docs: Add *item* to collection.
  
          raise :py:class:`~clique.error.CollectionError` if *item* cannot be
          added to the collection.