Toggle Group event called 2 times Unity UI

Why my toggle group event called 2 times on click of Toggle button?

I have created just test scene for this purpose and getting same result.

Here is my inspector image :


Following is Toggle component image :


I have written following code in script :

public void OnTankTypeToggleClick (int tankType)
		Debug.Log ("click method called : " + tankType);

Above debug statement is print on console two times. By this mean, click method is called two time.
I want to call click method just single time. So please give some awesome suggestion to me.

This problem, I was facing because one toggle state becomes OFF and another toggle state becomes ON.
So for these both events, the same method will get called.

This is the reason why the same method called two times. This is not a bug but by the choice implementation.
You have to put one check condition within the method code so it can only get called one time.

anyone know a solution?
i have this problem always when i use toggle groups. i saw some time ago someone wrote its a bug within unity, is there some workaround? or some fix i dont know about?