[fixes #3370] Support Helper in method

test/transform/resource/after-ecj/HelperInMethod.java

@@ -0,0 +1,19 @@
+import lombok.experimental.Helper;
+public class HelperInMethod {
+  public HelperInMethod() {
+    super();
+  }
+  int someMethod(int arg1) {
+    int localVar = 5;
+    @Helper class Helpers {
+      Helpers() {
+        super();
+      }
+      int helperMethod(int arg) {
+        return (arg + localVar);
+      }
+    }
+    final Helpers $Helpers = new Helpers();
+    return $Helpers.helperMethod(10);
+  }
+}