Google散点图 - {role：'style'} {role：'tooltip'}无法以JSON格式运行

I get google chart data from PHP function in json encoded format which I am passing to "arrayToDataTable" function. I am using $.ajax function. When I pass the following data to the "arrayToDataTable" function

var obj = $.parseJSON('[
    ["goals", "goal", {
        role: 'style'
    }, {
        role: 'tooltip'
    }],
    [54, 0.5, "#0000cf", "54%"],
    [100, 1.5, "#0000cf", "100%"],
    [97, 2.5, "#0000cf", "97%"],
    [87, 2.5, "#0000cf", "87%"]
]')

var data = google.visualization.arrayToDataTable(obj);

It is generating a following error.
SyntaxError: JSON.parse: expected property name or '}' at line 1 column 19 of the JSON data

If data is sent without "style" and "tooltip" columns it is generating a graph as expected.

I am following this post: Google Chart - uncaught error: not an array

In JSON, attribute names must be string.

Edit: string delimiter should always be " and not '

So

{
    role: 'style'
}

Should be

{
    "role": "style"
}