Properites groups and excludedGroups do not enable JUnit47 provider

I'm trying to define groups or excludeGroups for JUnit execution. When I define property, JUnit4 provider is used, and the groups are ignored. To enable group support I have to define parallel parameter or define JUnit47 provider explicitly as plugin dependency.

The plugin documentation is also inconsistent. The following goals documentation defines, that JUnit47 provider will be enabled:

http://maven.apache.org/plugins/maven-surefire-plugin/test-mojo.html#groups
http://maven.apache.org/plugins/maven-surefire-plugin/test-mojo.html#excludedGroups

But on http://maven.apache.org/plugins/maven-surefire-plugin/examples/junit.html, the formula for provider selection define only parallel parameter.