static public void FromVtArray(VtIntArray input, ref int[] output)
 {
     if (output.Length != input.size())
     {
         output = UsdIo.ArrayAllocator.Malloc <int>(input.size());
     }
     unsafe
     {
         fixed(int *p = output)
         {
             input.CopyToArray((IntPtr)p);
         }
     }
 }