Nested arrays in a Kynetx app datasource

ruleset a60x226 {
  meta {
    name "array inside an array"
    description <<
      for devex question
    >>
    author "Mike Grace"
    logging on
  }

  dispatch { }
  global { 
    exampleHash = {
      "articles" : [
        {
          "title" : "Not sure what to title this",
          "thumbs" : [
            { "url" : "http://geek.michaelgrace.org/MikeGrace.jpg" },
            { "url" : "http://geek.michaelgrace.org/is.jpg" },
            { "url" : "http://geek.michaelgrace.org/a.jpg" },
            { "url" : "http://geek.michaelgrace.org/fun.jpg" },
            { "url" : "http://geek.michaelgrace.org/guy.jpg" }
          ]
        },
        {
          "title" : "Not going to change the images for this one",
          "thumbs" : [
            { "url" : "http://geek.michaelgrace.org/MikeGrace.jpg" },
            { "url" : "http://geek.michaelgrace.org/is.jpg" },
            { "url" : "http://geek.michaelgrace.org/a.jpg" },
            { "url" : "http://geek.michaelgrace.org/fun.jpg" },
            { "url" : "http://geek.michaelgrace.org/guy.jpg" }
          ]
        },
        {
          "title" : "Isn't Devex great?!",
          "thumbs" : [
            { "url" : "http://geek.michaelgrace.org/MikeGrace.jpg" },
            { "url" : "http://geek.michaelgrace.org/is.jpg" },
            { "url" : "http://geek.michaelgrace.org/a.jpg" },
            { "url" : "http://geek.michaelgrace.org/fun.jpg" },
            { "url" : "http://geek.michaelgrace.org/guy.jpg" }
          ]
        }
      ]
    }
  }

  rule first_rule is active {
    select using ".*" setting ()
    foreach exampleHash.pick("$.articles") setting (article)
      foreach article.pick("$.thumbs") setting (thumb)
        pre {
          title = article.pick("$.title");
          thumbnail = thumb.pick("$.url");
        }
        notify(title,thumbnail) with width = 300 and sticky = true;
      // end of foreach that iterates for each thumbnail in article
    // end of foreach that iterates over each article
  }
}