java.lang.IllegalStateException: missing behavior definition for the preceding method call getMessage("title")

I'm using EasyMock(version 2.4) and TestNG for writing UnitTest.

I have a following scenario and I cannot change the way class hierarchy is defined.

I'm testing ClassB which is extending ClassA.

ClassB look like this

public class ClassB extends ClassA  {

  public ClassB()
    {
        super("title");
    }

    @Override
    public String getDisplayName() 
    {
        return ClientMessages.getMessages("ClassB.title");
    }

}

ClassA code

public abstract class ClassA {
    private String title;

    public ClassA(String title)
    {
        this.title = ClientMessages.getMessages(title);
    }

    public String getDisplayName()
    {
        return this.title;
    }
}

ClientMessages class code

public class ClientMessages {
    private static MessageResourse messageResourse;

    public ClientMessages(MessageResourse messageResourse) 
    {
        this.messageResourse = messageResourse;
    }
    public static String getMessages(String code) 
    {
        return messageResourse.getMessage(code);

    }
}

MessageResourse Class code

public class MessageResourse {
    public String getMessage(String code) 
    {
        return code;
    }
}

Testing ClassB

import static org.easymock.classextension.EasyMock.createMock;

import org.easymock.classextension.EasyMock;
import org.testng.Assert;
import org.testng.annotations.Test;

public class ClassBTest
{
    private MessageResourse mockMessageResourse = createMock(MessageResourse.class);
    private ClassB classToTest;
    private ClientMessages clientMessages;


    @Test
    public void testGetDisplayName()
    {

    EasyMock.expect(mockMessageResourse.getMessage("ClassB.title")).andReturn("someTitle");

        clientMessages = new ClientMessages(mockMess