docs: update single table inheritance

single-table-inheritance/src/main/java/com/iluwatar/SingleTableInheritance.java

@@ -81,7 +81,7 @@ public class SingleTableInheritance implements CommandLineRunner {
    * @param args program runtime arguments
    */
   @Override
-  public void run(String... args) throws Exception {
+  public void run(String... args) {
 
     Logger log = LoggerFactory.getLogger(SingleTableInheritance.class);
 

single-table-inheritance/src/main/java/com/iluwatar/entity/PassengerVehicle.java

@@ -45,10 +45,4 @@ public abstract class PassengerVehicle extends Vehicle {
     super(manufacturer, model);
     this.noOfPassengers = noOfPassengers;
   }
-
-  @Override
-  public String toString() {
-    return super.toString();
-  }
-
 }