Perhaps, but I’m not sure that’s always the case. I think it can be tricky to figure out exactly what that argument is when using some sort of transform. To figure it out, I used the following intermediate step:
text: (d) => {console.log(d); return "temp"}
At that point, the labels were all temp but I could check the console to see the value of d. Then, it was pretty easy to write the function.