groovy: how to access those javascript properties from a google page

#!/usr/bin/env groovy
import groovyx.net.http.*
import static groovyx.net.http.Method.GET
import static groovyx.net.http.ContentType.HTML

@Grab(group='org.codehaus.groovy.modules.http-builder', module='http-builder', version='0.5.0-SNAPSHOT' )
def http = new HTTPBuilder( 'https://www.google.com' )
  http.request( GET, HTML ) { req ->
  uri.path = "/"
  response.success = { resp, page ->
    def properties = new Properties()
    properties.load(
      new ByteArrayInputStream(
        page.HEAD.SCRIPT.text().replace(',','').replace('"','').getBytes()
      )
    )
    println "properties: "+properties
  }
}