to run a Test Class
mvn test -Dtest=classname
To run a specific test (@Test) in a class file
mvn -Dtest=TestCircle#xyz test
where TestCircle is the test class name and xyz is the test method,
wild card characters also work (both in the method name and class name).
To run all tests in a package
mvn '-Dtest=Tests.bielakias.*Test' test
this will run all classes named *Test.java under package Tests.bielakias