hmm lots of comments

EmittedStream.cs

        private bool DetectConcurrencyViolations(CheckpointTag expectedTag)
        {
            //NOTE: the comment below is not longer actual
            //      Keeping it for reference only
            //      We do back-read all the streams when loading state, so we know exactly which version to expect

            //TODO: if the following statement is about event order stream - let write null event into this stream
            //NOTE: the following condition is only meant to detect concurrency violations when
            // another instance of the projection (running in the another node etc) has been writing to 
            // the same stream.  However, the expected tag sometimes can be greater than last actually written tag
            // This happens when a projection is restarted from a checkpoint and the checkpoint has been made at 
            // position not updating the projection state 
            return expectedTag != _lastCommittedOrSubmittedEventPosition;
        }