Problem with error logging having a throwable in the interpolated string

Assuming the following code 

```
case class Example(i: Int) extends Throwable {
     override def toString: String = s"$i"
}
val exampleObject = Example(3)
logger.error(s"Example $exampleObject")
```

I would expect the message output to be

```
Example 3
```

Instead I get 

``` 
Example {}
```




