在findbugs中，我遇到了这样的问题 FCBL_FIELD_COULD_BE_LOCAL 在此代码的类名行中：

@Entity
@Table(name = "Student")
@Immutable
@Cache(usage = CacheConcurrencyStrategy.READ_ONLY)
public class RetrievableStudent extends BaseStudent
{
    @Id
    @Column(name = "STUDENT_ID")
    private long studentId;

    @Column(name = "STUD_NOTE")
    private String studenetNote;
}

如何解决此问题？