How did tiny San Marino maintain its independence when the rest of Italy was being unified during the Italian Wars of Unification?

by should-stop-posting
Assorted_Bits

You might want to read this answer by /u/RemoveYourself: https://www.reddit.com/r/AskHistorians/comments/1frcyx/why_has_nobody_ever_bothered_to_annex_san_marino/cad6975