New array with non-repeating values [duplicate]

I need to create a findUnique() function that creates a new array with non-repeating values.

This is how it should be:

console.log([10, 5, 6, 10, 6, 7, 2].findUnique()) // [5, 7, 2]

My try:

Array.prototype.findUnique = function() {
    let arr = this;
    let newarr = arr.filter((v, i, a) => {
       return a.indexOf(v) === i
    })
    return newarr
}

But it returns:

[10, 5, 6, 7, 2]

How can I make it return only non-repeated values?