def start(self):
if self.extra_args:<EOL><INDENT>sys.exit('<STR_LIT>'.format(self.name))<EOL><DEDENT>else:<EOL><INDENT>if self._toggle_value:<EOL><INDENT>nbextensions.install_nbextension_python(<EOL>_pkg_name, overwrite=True, symlink=False,<EOL>user=self.user, sys_prefix=self.sys_prefix, prefix=None,<EOL>nbextensions_dir=None, logger=None)<EOL><DEDENT>else:<EOL><INDENT>nbextensions.uninstall_nbextension_python(<EOL>_pkg_name, user=self.user, sys_prefix=self.sys_prefix,<EOL>prefix=None, nbextensions_dir=None, logger=None)<EOL><DEDENT>self.toggle_nbextension_python(_pkg_name)<EOL>self.toggle_server_extension_python(_pkg_name)<EOL><DEDENT>
Perform the App's actions as configured.