public static void RubberBandStretcher_SetFrequencyCutoff(IntPtr rbs, int n, float f)
 {
     if (IntPtr.Size == 8)
     {
         RubberBandNativeMethodsx64.RubberBandStretcher_SetFrequencyCutoff(rbs, n, f);
     }
     else
     {
         RubberBandNativeMethodsWin32.RubberBandStretcher_SetFrequencyCutoff(rbs, n, f);
     }
 }