public interface SpreadsheetElement<Child extends SpreadsheetElement<?, ?>, Parent extends SpreadsheetElement<?, ?>> extends SpreadsheetVisitable, Serializable {
Optional<Parent> getParent();
public interface SpreadsheetElement<Child extends SpreadsheetElement<?, ?>, Parent extends SpreadsheetElement<?, ?>> extends SpreadsheetVisitable, Serializable {
Optional<Parent> getParent();