This refactoring doesn't seem to work correctly.

- In a method without a parameter list `def f = {}`, nothing happens when this feature is invoked.
- When a complete value definition is selected
```
def x() = {
  val b = 0 // selection of this line
  b
}
```
this is the result
```
def x(extracted: Int = {
  val b = 0 // selection of this line
  b
}) = extracted
```
only extracting `b` would be the expected behavior.

But these are functional bugs in the implementation, they don't block this PR.