def get_or_set_default(self, section, option, value):
try:<EOL><INDENT>ret = self.get(section, option)<EOL><DEDENT>except MissingSetting:<EOL><INDENT>self.set(section, option, value)<EOL>ret = value<EOL><DEDENT>return ret<EOL>
Base method to fetch values and to set defaults in case they
don't exist.