My `src/test/` folder includes both unit and functional tests. The classpath of functional tests has the word `cucumber`, whereas the unit tests do not. So, how can I run the unit tests only? 

Thank you very much. 

**P.S.**: I know it is easy to use the "include" logic to select tests. For example, to only run the functional tests in my case, I can simply use this  

`./gradlew test -Dtest.single=cucumber/**/`  

However, I don't know how to exclude tests in a simple way. 

BTW, I am using gradle 1.11.