How to get name of checkboxes=>checkbox field in Types Custom Fields in Wordpress?

Scheme:

rest{
 "name_1" => "rest_1",
 "name_2" => "rest_2"
 "name_3" => "rest_3"
 "name_4" => "rest_4"
}

This function

types_render_field("rest", array("output"=>"html");

returns values of checked fields: "rest_1, rest_3" (for example), but i need to get "name_1, name_3".

Please, can u give me any ideas?