randnAsync function
RandN Fills the array with normally distributed random numbers.
For further details, please see: https://docs.opencv.org/master/d2/de8/group__core__array.html#gaeff1f61e972d133a04ce3a5f81cf6808
Implementation
Future<Mat> randnAsync(InputOutputArray dst, Scalar mean, Scalar stddev) async => cvRunAsync0(
(callback) => ccore.RandN_Async(dst.ref, mean.ref, stddev.ref, callback),
(c) => c.complete(dst),
);