def stream(stream_name)
      Specification.new(reader, result.dup { |r| r.stream = Stream.new(stream_name) })
    end
def stream(stream_name)
      Specification.new(reader, result.dup { |r| r.stream = Stream.new(stream_name) })
    end
@api private
 @private
 Limits the query to certain stream.
 {http://railseventstore.org/docs/read/ Find out more}.

 @param stream_name [String] name of the stream to get events from
 @return [Specification]