Meteor.startup(function () {
  if (Images.find().count() === 0) {
    for (let i = 1; i < 23; i++) {
      Images.insert({
        "img_src": "img_" + i + ".jpg",
        "img_alt": "image number " + i
      });
    } // end of for insert images
    // count the images!
    console.log("startup.js says: " + Images.find().count());
  } // end of if have no images.
});