如何在纯java的Citrus中设置全局变量？

public class GlobalVariables {
    public static String myVariable = "Hello, World!";
}

import com.example.GlobalVariables;
import com.consol.citrus.annotations.CitrusTest;
import com.consol.citrus.dsl.testng.TestNGCitrusTestDesigner;
import org.testng.annotations.Test;

public class MyTest extends TestNGCitrusTestDesigner {

    @Test
    @CitrusTest
    public void myTest() {
        echo("${myVariable}");
    }

    @BeforeClass
    public void beforeClass() {
        // 设置全局变量的值
        GlobalVariables.myVariable = "Hello, Citrus!";
    }
}