var countries = new Bloodhound({
datumTokenizer: Bloodhound.tokenizers.whitespace,
queryTokenizer: Bloodhound.tokenizers.whitespace,
prefetch: 'http://pages.revox.io/json/countries-list.json'
});
// passing in `null` for the `options` arguments will result in the default
// options being used
$('#mytyphead').typeahead(null, {
name: 'countries',
source: countries
});