fix(demo): fix Vaadin 24 runtime error in demo

Close #139

src/test/java/com/flowingcode/vaadin/addons/twincolgrid/CompatibilityExtension.java

@@ -0,0 +1,28 @@
+package com.flowingcode.vaadin.addons.twincolgrid;
+
+import com.vaadin.flow.component.select.Select;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+/** Binary compatibility utils for Vaadin 14-24 */
+public class CompatibilityExtension {
+
+  private static final Method setItems = lookupSetItems();
+
+  private static Method lookupSetItems() {
+    try {
+      return Select.class.getMethod("setItems", Object[].class);
+    } catch (NoSuchMethodException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  public static <T> void setItems(Select<T> select, T[] items) {    
+    try {
+      setItems.invoke(select, (Object) items);
+    } catch (IllegalAccessException | InvocationTargetException e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+}

src/test/java/com/flowingcode/vaadin/addons/twincolgrid/OrientationDemo.java

@@ -31,11 +31,13 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
+import lombok.experimental.ExtensionMethod;
 
 @SuppressWarnings("serial")
 @PageTitle("Orientation")
 @DemoSource
 @Route(value = "twincolgrid/orientation", layout = TwincolDemoView.class)
+@ExtensionMethod(CompatibilityExtension.class) // hide-source
 public class OrientationDemo extends VerticalLayout {
 
   private final Set<Book> selectedBooks = new HashSet<>();