public static ClassicHttpResponse make200Response() {
        final ClassicHttpResponse out = new BasicClassicHttpResponse(HttpStatus.SC_OK, "OK");
        out.setHeader("Date", DateUtils.formatStandardDate(Instant.now()));
        out.setHeader("Server", "MockOrigin/1.0");
        out.setHeader("Content-Length", "128");
        out.setEntity(makeBody(128));
        return out;
    }
Generates a response body with random content.
 @param nbytes length of the desired response body
 @return an {@link HttpEntity}
httpclient5-cache/src/test/java/org/apache/hc/client5/http/impl/cache/HttpTestUtils.java