How to write a Nunit test for this kind of method()

Question

public List<Location> MinshpqtyUpsertLocations(KeyValuePair<int, string>[] locations, int minshpqty)

{

     

}

 

locations array consists of locationid which is int and location name which is string both of them together a keyvalue pair am done with everything just I have to write a nunit test or any test to check the performance by passing locations array size as 1000

 

please guide me, if some one comeup with the same problem, thanks in advance :)