[TestMethod] public void cache() {
var db = new session();
var count = db
.cache("count")
.one<int>("select count(email) from users");
db.execute("insert into users (email, password) values ('*****@*****.**', 'blood')");
var new_count = db
.cache("count")
.one<int>("select count(email) from users");
assert(count == new_count);
var diff = db.one<int>("select count(email) from users");
assert(diff > count);
}