Added tests for @ExtensionMethod

test/transform/resource/before/ExtensionMethodPlain.java

@@ -0,0 +1,23 @@
+import lombok.experimental.ExtensionMethod;
+
+@ExtensionMethod({java.util.Arrays.class, ExtensionMethodPlain.Extensions.class})
+class ExtensionMethodPlain {
+  public String test() {
+    int[] intArray = {5, 3, 8, 2};
+    intArray.sort();
+    
+    String iAmNull = null;
+    return iAmNull.or("hELlO, WORlD!".toTitleCase());
+  }
+
+  static class Extensions {
+    public static <T> T or(T obj, T ifNull) {
+      return obj != null ? obj : ifNull;
+    }
+    
+    public static String toTitleCase(String in) {
+      if (in.isEmpty()) return in;
+      return "" + Character.toTitleCase(in.charAt(0)) + in.substring(1).toLowerCase();
+    }
+  }
+}