gradle test runs my test class, but a custom test task doesnt

This is my test class:

public class RoutingResponseRegressionOneByOne {


    @BeforeClass
    public static void oneTimeSetUp() {
        routingClient = injector.getInstance(IRoutingClient.class);
        System.out.println("in RoutingResponseRegressionOneByOne:: oneTimeSetUp");
    }

I added a task to my build.gradle

task testRegression(type: Test) {
    systemProperties['test.single'] = '\'RoutingResponseRegressionOneByOne\''
    //systemProperty 'test.single', System.getProperty('test.single', '\'RoutingResponseRegressionOneByOne\'')
}

When I run "test" from the intellij this is the output

however when I "testRegression" from the intellij this is the output:

what should I fix in order for "testRegression" to run only this test class ?