@PipelineProperty(description = "Choose the maximum size that a stream can be before it is rolled.",
            defaultValue = "100M",
            displayPriority = 3)
    public void setRollSize(final String rollSize) {
        super.setRollSize(rollSize);
    }
Joins text instances into a single text instance.
stroom-pipeline/src/main/java/stroom/pipeline/writer/RollingStreamAppender.java