You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: redis_buffer.rb
    path of file: ./repos/kitsu-server/lib/buffered_stream_client
    
    the code of the file until where you have to start completion: class BufferedStreamClient
  # A system for buffering actions to be sent in groups to Stream's API.  This can be used for
  # anything which is batchable, even i
    
    def push(*items, group: 'default')
      key = key_for(group)
      items = items.map(&:to_json)
      multi do |conn|
        # Add the follow to the queue
        conn.lpush(key, items)
        # Increment our queue length in the list
        conn.zincrby(groups_key, items.count, key)
      end
    end