This could possibly work for GLE?
```
if gle = client.write_concern.get_last_error
   acknowledge = Operation::Command.new(gle, context)
   acknowledge.execute
end
```
One concern here is that in the ```execute``` method on the Command class, you have a "@todo: GLE" note.  This might cause us to get into a weird circular chain of GLE commands that check themselves for GLE.