Programmatically determine Gradle version from within Gradle plugin

How can I retrieve the version of Gradle itself programmatically from within a Gradle plugin?

Just found out one can get at it using either

• getProject().getGradle().getGradleVersion()
  Javadoc and DSL reference for the Gradle core type which contains the version. Accordinng to the javadoc getVersion will never return null.

or

• Plugin.class.getPackage().getImplementationVersion()
  This is plain groovy/java class-based and depends on the classloader and provided Manifest.