public Coverage getCoverage(boolean create) {
        if (coverage == null && create)
            coverage = new Coverage(0L, 0, 0, (hits().size() == 0 ? 0 : 1));
        return coverage;
    }
Returns coverage information

@param create if true the coverage information of this result is created if missing
@return the coverage information of this, or null if none and create is false
container-search/src/main/java/com/yahoo/search/Result.java