radlab/SCADS — comment on commit 0a306788beb290a1b18ed52a63c5e7debcc904b6
File: scalaengine/src/main/scala/transactions/TxDB.scala line 63
By marmbrus:

if you don't specify a return type for an abstract function the compiler assumes it returns Unit.

Ex:
```
scala> trait X1 { def x }
defined trait X1
scala> class X2 extends X1 { def x = "test" }
defined class X2
scala> (new X2).x
```

Instead of making it return some default value you could also just specify the return type:
```
scala> trait Y1 {def y: String}
defined trait Y1
scala> class Y2 extends Y1 {def y = "test"}
defined class Y2
scala> (new Y2).y
res2: java.lang.String = test
```