Download file with Vert.x (not working with vert.x 1.2.3)

Download.groovy

import static org.vertx.groovy.core.streams.Pump.createPump

vertx.createHttpClient(host: 'humanstxt.org', port: 80)
    .getNow('/humans.txt') { resp ->
    println "GOT response with status $resp.statusCode"
    resp.pause();
    resp.endHandler {
          println "response END with first registered handler"
    }

    def filename = "${UUID.randomUUID()}.txt"

    vertx.fileSystem.open(filename) { ares ->
        println "file opened"
        def file = ares.result
        def pump = createPump(resp, file.writeStream)
        resp.endHandler {
          println "response END with handler after file opening"
          file.close {
            println "Stored ${pump.bytesPumped} bytes to $filename"
          }
        }
        pump.start()
        resp.resume()
    }
}