code: def counter(path, delta, create_parents=False, **kwargs):
      
      if not delta:
          raise ValueError("Delta must be positive or negative!")
      return _gen_4spec(LCB_SDCMD_COUNTER, path, delta,
                        create_path=create_parents, **kwargs)
docs: Increment or decrement a counter in a document.
  
      :param path: Path to the counter
      :param delta: Amount by which to modify the value. The delta
          can be negative but not 0. It must be an integer (not a float)
          as well.
      :param create_parents: Create the counter (and apply the modification) if it
          does not exist
  
      .. note::
  
          Unlike :meth:`couchbase.bucket.Bucket.counter`,
          there is no `initial` argument. If the counter does not exist
          within the document (but its parent does, or `create_parents`
          is true), it will be initialized with the value of the `delta`.
  
      This operation is only valid in :cb_bmeth:`mutate_in`.
  
      .. seealso:: :func:`upsert`, :cb_bmeth:`counter` (in `Bucket`)