@Override
    public void beginStepping() {
        if (currentStreamId != null) {
            final StepLocation stepLocation = new StepLocation(
                    currentStreamId,
                    currentPartIndex != null
                            ? currentPartIndex
                            : 0,
                    currentRecordIndex != null
                            ? currentRecordIndex
                            : 0);

            BeginPipelineSteppingEvent.fire(
                    this,
                    null,
                    null,
                    StepType.REFRESH,
                    stepLocation,
                    null);
        } else {
            AlertEvent.fireError(this, "No stream id", null);
        }
    }
The ranges returned are line/col positions in the input text. Thus the input text should
not be changed/formatted after the highlight ranges have been generated.
stroom-core-client/src/main/java/stroom/dashboard/client/text/TextPresenter.java