Unfortuantely, we decided not to go with the return type on a new line style (see dev list). The acceptable style is one of these two:

```
 def accumulable[T, R](initialValue: T)
                      (implicit param: AccumulableParam[T, R]): Accumulable[T, R] =
  new Accumulable(initialValue, param)
```
or
```
 def accumulable[T, R]
    (initialValue: T)
    (implicit param: AccumulableParam[T, R]): Accumulable[T, R] =
  new Accumulable(initialValue, param)
```