public Query nearestNeighbor(String rankFeature) {
        return common("nearestNeighbor", annotation, (Object) rankFeature);
    }
Nearest neighbor query.
https://docs.vespa.ai/en/reference/query-language-reference.html#nearestneighbor

@param rankFeature the rankfeature.
@return the query
client/src/main/java/ai/vespa/client/dsl/Field.java