private static Map<String, ClusterReindexing> toClusterReindexing(SimpleHttpResponse response) throws IOException {
        if (response.getCode() != HttpStatus.SC_OK) throw new IOException("Expected status code 200, got " + response.getCode());
        if (response.getBody() == null) throw new IOException("Response has no content");
        return toClusterReindexing(response.getBodyBytes());
    }
Retrieves reindexing status from cluster controllers over HTTP

@author bjorncs
configserver/src/main/java/com/yahoo/vespa/config/server/application/DefaultClusterReindexingStatusClient.java