[fixes #3370] Support Helper in method

test/transform/resource/before/HelperInMethod.java

@@ -0,0 +1,16 @@
+import lombok.experimental.Helper;
+
+public class HelperInMethod {
+	int someMethod(int arg1) {
+		int localVar = 5;
+		
+		@Helper
+		class Helpers {
+			int helperMethod(int arg) {
+				return arg + localVar;
+			}
+		}
+		
+		return helperMethod(10);
+	}
+}