static public void FromVtArray(VtUInt64Array input, ref ulong[] output)
 {
     if (output.Length != input.size())
     {
         output = UsdIo.ArrayAllocator.Malloc <ulong>(input.size());
     }
     unsafe
     {
         fixed(ulong *p = output)
         {
             input.CopyToArray((IntPtr)p);
         }
     }
 }
 // Convenience API: generates garbage, do not use when performance matters.
 static public ulong[] FromVtArray(VtUInt64Array input)
 {
     ulong[] output = UsdIo.ArrayAllocator.Malloc <ulong>(input.size());
     FromVtArray(input, ref output);
     return(output);
 }