TubeClass.java

public class TubeClass {
    public static boolean methodCalled = false;
    public static boolean constructorCalled = false;
    
    public TubeClass() {
        constructorCalled = true;
        System.err.println("I really wish you wouldn't call me.");
    }
    
    public void dontCallMe() {
        methodCalled = true;
        System.err.println("You won't call me.");
    }
}

TubeClassTest.groovy

import groovy.util.GroovyTestCase

import static org.easymock.EasyMock.expect
import static org.easymock.classextension.EasyMock.createMock
import static org.easymock.classextension.EasyMock.replay
import static org.easymock.classextension.EasyMock.verify

class TubeClassTest extends GroovyTestCase {
  void testShouldNotCallMethod() {
    def mockObject = createMock(TubeClass)
    
    expect(mockObject.dontCallMe()).atLeastOnce()
    replay(mockObject)
    
    mockObject.dontCallMe()
    assert TubeClass.methodCalled == false
    assert TubeClass.constructorCalled == false
  }
}