a copy-paste typo got in - this does nothing to do with in the set_params code
avoid possible NPE as self.getInstanceVariable might return null (not just nil)
still not done with extension.value - handle authorityKeyIdentifier's issuer part (as MRI)
need to account for nested subject keyid octets in a "smart" way
MRI expects upper-first DirName ... copy over the verified test case from JRuby core