Fix JavaClassWrapper so it actually works

doc/classes/JavaClassWrapper.xml

@@ -6,6 +6,15 @@
 	<description>
 		The JavaClassWrapper singleton provides a way for the Godot application to send and receive data through the [url=https://developer.android.com/training/articles/perf-jni]Java Native Interface[/url] (JNI).
 		[b]Note:[/b] This singleton is only available in Android builds.
+		[codeblock]
+		var LocalDateTime = JavaClassWrapper.wrap("java.time.LocalDateTime")
+		var DateTimeFormatter = JavaClassWrapper.wrap("java.time.format.DateTimeFormatter")
+
+		var datetime = LocalDateTime.now()
+		var formatter = DateTimeFormatter.ofPattern("dd-MM-yyyy HH:mm:ss")
+
+		print(datetime.format(formatter))
+		[/codeblock]
 	</description>
 	<tutorials>
 	</tutorials>