No effective change - code cleanup - return void (unused return values), remove unused methods

src/main/java/com/avaje/ebeaninternal/server/expression/DefaultExampleExpression.java

@@ -121,13 +121,6 @@ public class DefaultExampleExpression implements SpiExpression, ExampleExpressio
     return this;
   }
 
-  /**
-   * This will return null for this example expression.
-   */
-  public String getPropertyName() {
-    return null;
-  }
-
   /**
    * Adds bind values to the request.
    */