+/* Cookie jar serves as cookie storage and a means of retrieving
+ cookies efficiently. All cookies with the same domain are stored
+ in a linked list called "chain". A cookie chain can be reached by
+ looking up the domain in the cookie jar's chains_by_domain table.
+
+ For example, to reach all the cookies under google.com, one must
+ execute hash_table_get(jar->chains_by_domain, "google.com"). Of
+ course, when sending a cookie to `www.google.com', one must search
+ for cookies that belong to either `www.google.com' or `google.com'
+ -- but the point is that the code doesn't need to go through *all*
+ the cookies. */
+