newBuf := dst
	if len(dst) != len(p.readers) {
		newBuf = make([][]byte, len(p.readers))
	} else {
		for i := range newBuf {
			newBuf[i] = newBuf[i][:0]
		}
	}
	var newBufLK sync.RWMutex

	if p.offset+p.shardSize > p.shardFileSize {
		p.shardSize = p.shardFileSize - p.offset
	}
	if p.shardSize == 0 {
		return newBuf, nil
	}

        }
        [OldBase, OldSub, NewBase, NewSub].each {
            classes[it.simpleName] = instanceScopedPool.get(it.name)
        }

        classes['OldBase'].superclass = classes['OldSuperInternal']
        classes['NewBase'].superclass = classes['NewSuperInternal']
        classes['OldSub'].superclass = classes['OldBase']
        classes['NewSub'].superclass = classes['NewBase']