StringUtil.asHTML is not a function!

[tdk]

Using StringUtil.asHTML() to make some text HTML-safe, throws the following JavaScripException:

Caused by: com.google.gwt.core.client.JavaScriptException: (TypeError): (new $wnd.String(str)).asHTML is not a function
 fileName: http://127.0.0.1:8888
 lineNumber: 26
 stack: ("Caused by: com.google.gwt.core.client.JavaScriptException: (TypeError): (new $wnd.String(str)).asHTML is not a function
 fileName: http://127.0.0.1:8888
 lineNumber: 26
 stack: ("A\ntext\nwith\5\nlines\n")@http://127.0.0.1:8888:26
([object GWTJavaObject],1048775,[object GWTJavaObject])@http://127.0.0.1:8888/portal/hosted.html?portal:56
([object Object],(void 0))@http://127.0.0.1:8888:1331
((function () {var param = {};var event = __gwt_makeJavaInvoke(1)(null, 3276919, param);__gwt_makeJavaInvoke(1)(selfJ, 1048775, even
t);var ret = __gwt_makeJavaInvoke(0)(event, 1179654);return !ret;}),[object Object],[object Arguments])@http://127.0.0.1:8888:20
(null,106,(function () {var param = {};var event = __gwt_makeJavaInvoke(1)(null, 3276919, param);__gwt_makeJavaInvoke(1)(selfJ, 1048
775, event);var ret = __gwt_makeJavaInvoke(0)(event, 1179654);return !ret;}),[object Object],[object Arguments])@http://127.0.0.1:88
88/portal/hosted.html?portal:56
([object Object],(void 0))@http://127.0.0.1:8888:4
([object Object],(void 0))@http://127.0.0.1:8888:13
isc_StatefulCanvas_handleActivate([object Object],(void 0))@http://127.0.0.1:8888/portal/sc/modules/ISC_Foundation.js:296
isc_StatefulCanvas_handleClick([object Object],(void 0))@http://127.0.0.1:8888/portal/sc/modules/ISC_Foundation.js:298
isc_c_EventHandler_bubbleEvent([object Object],"click")@http://127.0.0.1:8888/portal/sc/modules/ISC_Core.js?isc_version=7.1.js:1497
isc_c_EventHandler_handleClick([object Object])@http://127.0.0.1:8888/portal/sc/modules/ISC_Core.js?isc_version=7.1.js:1345
isc_c_EventHandler__handleMouseUp([object MouseEvent],(void 0))@http://127.0.0.1:8888/portal/sc/modules/ISC_Core.js?isc_version=7.1.
js:1332
isc_c_EventHandler_handleMouseUp([object MouseEvent])@http://127.0.0.1:8888/portal/sc/modules/ISC_Core.js?isc_version=7.1.js:1323
isc_c_EventHandler_dispatch(isc_c_EventHandler_handleMouseUp,[object MouseEvent])@http://127.0.0.1:8888/portal/sc/modules/ISC_Core.j
s?isc_version=7.1.js:1560
anonymous([object MouseEvent])@http://127.0.0.1:8888/portal/sc/modules/ISC_Core.js?isc_version=7.1.js:38

        at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:237)
        at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:129)
        at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:561)
        at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:269)
        at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91)
        at com.smartgwt.client.util.StringUtil.asHTML(StringUtil.java)
        at de.ics.continuity.web.client.editor.DiscussionEditor.save(DiscussionEditor.java:173)
        at de.ics.continuity.web.client.editor.DiscussionEditor.access$1(DiscussionEditor.java:168)
        at de.ics.continuity.web.client.editor.DiscussionEditor$3.onClick(DiscussionEditor.java:79)
        at com.smartgwt.client.widgets.events.ClickEvent.dispatch(ClickEvent.java:98)
        at com.smartgwt.client.widgets.events.ClickEvent.dispatch(ClickEvent.java:1)
        at com.google.gwt.event.shared.SimpleEventBus.doFire(SimpleEventBus.java:204)
        ... 28 more

This behaviour is reproducable with the following code

import com.google.gwt.core.client.EntryPoint;
import com.smartgwt.client.util.StringUtil;

public class MainEntryPoint implements EntryPoint {
    @Override
    public void onModuleLoad() {
        String text = "A\ntext\nwith\n5\nlines\n";
        System.out.println(StringUtil.asHTML(text));
    }
}

Am I missing something?

I'm using GWT 2.2.0, SmartGWT 2.4, Java 1.6.0_25, NetBeans 6.9.1 on Windows 7 x64