path: waagent_2.12.0.2-4/tests/ga/test_env.py
    def test_get_dhcp_client_pid_should_return_an_empty_list_and_log_a_warning_when_dhcp_client_is_not_running(self):
        with patch("azurelinuxagent.common.osutil.default.shellutil.run_command", side_effect=lambda _: self.shellutil_run_command(["pidof", "non-existing-process"])):
            with patch('azurelinuxagent.common.logger.Logger.warn') as mock_warn:
                pids = MonitorDhcpClientRestart(get_osutil())._get_dhcp_client_pid()