Open an XML registry file for reading if it exists.
Open an XML registry file for reading if it exists.
java.io.FileNotFoundException if it does not exist.
Open an XML registry file for reading if it exists, or return None if it does not.
Find and open an information model registry XML file, given the base name of the file. This presumes that such files will exist as resources under /org/cert/netsa/io/ipfix/registries.