Nevermind. The ditto isn't necessary though (apparently), just:

```D
///
unittest
{
}
```
Is enough.

I think the idea is being able (later) to split the documentation. Eg:
```D
/**
The function foo.
*/
void foo();
/**
Can be used like this:
*/
unittest
{
    //like this
}
/**
or like that:
*/
unittest
{
    //like that
}
```

The two signatures below need the ditto though.