# File test/testhelper.rb, line 16
def image_has_collection_of(url,collection_type)
  image=@@filecache.get_file_system_image(url)    
  assert(image.respond_to?(collection_type),"#{url} should contain a collection of #{collection_type}")
  collection=image.send(collection_type)
  assert(collection.length>0,"#{url} should contain more than zero #{collection_type}")
end