JVM fork options for Gradle task test from Java plugin

I have two Gradle tasks with a test type (from Java Gradle):

task testsA(type: Test) {
  useTestNG {
    includeGroups 'typeA'
  }
  systemProperty 'hostname' 'localhost'
}

task testsB(type: Test) {
  useTestNG {
    includeGroups 'typeB'
  }
  systemProperty 'hostname' 'localhost'
}

      

        
        
        
      

    

This method systemProperty()

comes from a Java plugin and calls the systemProperty()

on object DefaultJavaForkOption

, which is private and final.

Is there a way to set the fork system property "hostname" once (in a different way or as a variable) and then use it in both of these tasks?

Note that I am not interested in defining the Gradle variable "hostname" and then reusing it as a value for the systemProperty method.