I know it's awful and imperative and all, but does this look easier?
```
ImmutableList.Builder images = ImmutableList.builder();
for (StandardDrive drive : api.listStandardDriveInfo()) {
   if (drive.getMedia() == MediaType.DISK) {
      images.add(standardDriveToWellKnownImage.apply(drive));
   }
}
return images.build();
```
?

In any case, use an ImmutableList?