+ /**
+ * Generate a new token from the client ID and secret.
+ * <p>
+ * Note that those tokens are long-lived, and it would be badly seen to
+ * create a lot of them without due cause.
+ * <p>
+ * So, please cache and re-use them.
+ *
+ * @param clientId
+ * the client ID offered on FimFiction
+ * @param clientSecret
+ * the client secret that goes with it
+ *
+ * @return a new generated token linked to that client ID
+ *
+ * @throws IOException
+ * in case of I/O errors
+ */