How can I import Maven and Gradle bundled plugins in my IDE using gradle-intellij-plugin

I'm developing a new plugin using gradle-intellij-plugin.
Following the README.md, I've added the dependencies of Maven and Gradle bundled plugins as follows

intellij {
    version = '2018.3.2'
 
    plugins 'Maven', 'gradle'

}

In the plugin.xml I do see the imported plugins

But in the code I cannot import the classes provided with the bundled plugins

Should I add these sources ad project dependencies?