The rewrite is correct, I think.  The original,
```
fill_value = np.array((-999, -12345678.9, "???"), dtype=object) 
```
indeed produces an array with three objects, but that does not pass the test. By first creating an array to hold objects, I can fill the first entry with a single tuple holding all three values. I did not know how to invoke `nd.array` such that it treats the tuple as a single object....