def _load_nexus_cfg_driver(self):
try:<EOL><INDENT>loaded_class = runtime_utils.load_class_by_alias_or_classname(<EOL>'<STR_LIT>', '<STR_LIT>')<EOL>return loaded_class(CONF.ml2_cisco.nexus_switches)<EOL><DEDENT>except ImportError:<EOL><INDENT>LOG.error("<STR_LIT>")<EOL>raise SystemExit(<NUM_LIT:1>)<EOL><DEDENT>
Load Nexus Config driver.
        :raises SystemExit of 1 if driver cannot be loaded