private static void renderCoverageAttributes(Coverage coverage, XMLWriter writer) {
        if (coverage == null) return;
        writer.attribute(COVERAGE_DOCS,coverage.getDocs());
        writer.attribute(COVERAGE_NODES,coverage.getNodes());
        writer.attribute(COVERAGE_FULL,coverage.getFull());
        writer.attribute(COVERAGE,coverage.getResultPercentage());
        writer.attribute(RESULTS_FULL,coverage.getFullResultSets());
        writer.attribute(RESULTS,coverage.getResultSets());
    }
Creates a json renderer using a custom executor.
Using a custom executor is useful for tests to avoid creating new threads for each renderer registry.
container-search/src/main/java/com/yahoo/search/pagetemplates/result/PageTemplatesXmlRenderer.java