golang, how to find out if 'map[string][][]int' has a value? : golang, how to find out if 'map[string][][]int' has a value?

var a map[string][][]int

    var aa map[string][][]int = map[string][][]int{"a": [][]int{{10, 10}, {20, 20}}}
	var bb map[string][][]int = map[string][][]int{"b": [][]int{{30, 30}, {40, 40}}}

	fmt.Println(aa) // >> map[a:[[10 10] [20 20]] b:[[10 10] [20 20]]]

then,
How do i know if '[30, 30]' is in 'aa'?

I want to check, whether 'aa' has '[30 30]'.

please help me.