def METHOD_NAME(buffer_connection, command_output_and_expected_result_on_connect_failed):
    iperf_cmd = Iperf(connection=buffer_connection.moler_connection, options='-c 10.156.236.132')
    command_output, expected_result = command_output_and_expected_result_on_connect_failed
    buffer_connection.remote_inject_response([command_output])
    assert 'iperf -c 10.156.236.132' == iperf_cmd.command_string
    with pytest.raises(CommandFailure):
        iperf_cmd()