Numba function signature - accepting a list of lists if ints

Hi I have a function which accepts the following parameters:

def calc(points: List[List[int]], x: int, y: int, unavail: List[int], N: int) -> (int, int):
    pass

I am trying to write a signature for it in Numba but I'm hitting problems. The signature below throws an exception. What is wrong with it?

@jit('UniTuple(int64,2)(ListType[ListType[int64]],int64,int64,ListType[int64],int64)', nopython=True, nogil=True)
def calc(point, x, y, unavail, N):
    pass

Exception:

TypeError: '_TypeMetaclass' object is not subscriptable