public static boolean benchmarkCoverage(boolean benchmarkOutput, HeaderFields headers) {
        return benchmarkOutput && headers.get(BenchmarkingHeaders.REQUEST_COVERAGE) != null;
    }
Static helper methods which implement the mapping between the ErrorMessage
API and HTTP headers and return codes.

@author Einar M R Rosenvinge
@author Steinar Knutsen
@author Simon Thoresen Hult
@author bratseth
container-core/src/main/java/com/yahoo/container/jdisc/VespaHeaders.java