$data = [
        "products" => [
            [ "id"=>1, "name"=>"vaj", "price"=>1.8 ],
            [ "id"=>2, "name"=>"kenyér", "price"=>0.8 ],
            [ "id"=>3, "name"=>"tej", "price"=>0.9 ]
            ],
        "customers" => [
            ["id"=>1, "name"=>"Penge Béla", "city"=>"Szeged"],
            ["id"=>2, "name"=>"Ezres Irén", "city"=>"Szeged"],
            ["id"=>3, "name"=>"Látó Ervin", "city"=>"Szeged"],
        ]
    ];