如何通过Guzzle 6为一个参数发布几个值？

How post several values for one parameter by Guzzle 6 ? For example i have parameter with name "param" and values for him "1,2". In post headers i need get:

param:1
param:2

I tryed:

$response = $client->post('http://test.com', [
                'form_params' => $dataPost
]);

Where $dataPost is was:

$dataPost=[
'param'=>[1,2]
]

or

$dataPost=[
0=>['param'=>1],
1=>['param'=>2]
]

It does not work

You should not assign multiple values for one field, however if you do, last value is prior to previous ones. If you are dealing with your own host and you have control over the way you get POSTed data you may use param as an array like param[] or send imploded values like 'param' => '1,2' and parse them later on receiving.