public String toString() {
        return String.format(
            "Features{%s}",
            features
                .entrySet()
                .stream()
                .map(entry -> String.format("(%s -> %s)", entry.getKey(), entry.getValue()))
                .collect(joining(", "))
        );
    }
@param  feature   name of the feature

@return           the VersionRangeType corresponding to the feature name, or null if the
                  feature is absent
clients/src/main/java/org/apache/kafka/common/feature/Features.java