Overriding a method with Generic Parameters in Java?

Monitor x = new EmailMonitor();
List<NonEmailAccount> nonEmailAccounts = ...;
x.performMonitor(nonEmailAccounts);

Monitor x = new EmailMonitor();
List<NonEmailAccount> nonEmailAccounts = ...;
x.performMonitor(nonEmailAccounts);

Monitor x = new EmailMonitor();
List<NonEmailAccount> nonEmailAccounts = ...;
x.performMonitor(nonEmailAccounts);

public abtract class Monitor<T extends MonitorAccount>
{
    ...
    public abstract List<? extends T> performMonitor(
        List<? extends T> accounts);
}

public class EmailMonitor extends Monitor<EmailAccount>
{
    @Override
    public abstract List<? extends EmailAccount> performMonitor(
        List<? extends EmailAccount> accounts)
    {
        // Code goes here
    }
}

public abstract class Monitor <T extends MonitorAccount> {
  ...
  public abstract List<T> performMonitor(List<T> accounts);
  ..
}

public class EmailMonitor extends Monitor<EmailMonitor> {
  ...
  public List<EmailAccount> performMonitor(List<EmailAccount> emailAccounts) {
    ..//logic...logic...logic
    return emailAccounts;
  }
  ...
}