EXECUTE: Create any CDI project.
EXECUTE: Create:

package org.test;

public class FirstBean {

}

package org.test;

import javax.enterprise.context.SessionScoped;

@SessionScoped
public class SecondBean extends FirstBean {

}

EXECUTE: Build the project
ASSERT: "SecondBean" name in SecondBean.java class marked with "Managed bean SecondBean which declares a passivating scope SessionScoped must be passivation capable [JSR-299 §6.6.4]" warning problem marker with "Add java.io.Serializable interface to 'SecondBean' class"
EXECUTE: Select quick fix link
FAIL: Quick fix inserted 'implements Serializable' before 'extends FirstBean' and it couse compilation problem