java.lang.NullPointerException
	at io.onedev.commons.utils.ClassUtils.findSubClasses(ClassUtils.java:59)
	at io.onedev.commons.utils.ClassUtils.findImplementations(ClassUtils.java:135)
	at io.onedev.commons.loader.DefaultImplementationRegistry.getImplementations(DefaultImplementationRegistry.java:26)
	at io.onedev.server.web.page.help.ApiHelpUtils.getImplementations(ApiHelpUtils.java:150)
	at io.onedev.server.web.page.help.ApiHelpUtils.getExampleValue(ApiHelpUtils.java:99)
	at io.onedev.server.web.page.help.ApiHelpUtils.getExampleValue(ApiHelpUtils.java:117)
	at io.onedev.server.web.page.help.ApiHelpUtils.getExampleValue(ApiHelpUtils.java:31)
	at io.onedev.server.web.page.help.MethodDetailPage.onInitialize(MethodDetailPage.java:310)
	at org.apache.wicket.Component.fireInitialize(Component.java:878)
	at org.apache.wicket.MarkupContainer.internalInitialize(MarkupContainer.java:1071)
	at org.apache.wicket.Page.isPageStateless(Page.java:465)
	at org.apache.wicket.core.request.mapper.AbstractBookmarkableMapper.getPageInfo(AbstractBookmarkableMapper.java:498)
	at org.apache.wicket.core.request.mapper.AbstractBookmarkableMapper.mapHandler(AbstractBookmarkableMapper.java:443)
	at org.apache.wicket.core.request.mapper.MountedMapper.mapHandler(MountedMapper.java:160)
	at org.apache.wicket.request.mapper.CompoundRequestMapper.mapHandler(CompoundRequestMapper.java:210)
	at org.apache.wicket.request.mapper.CompoundRequestMapper.mapHandler(CompoundRequestMapper.java:210)
	at org.apache.wicket.request.cycle.RequestCycle.mapUrlFor(RequestCycle.java:417)
	at org.apache.wicket.request.handler.render.WebPageRenderer.respond(WebPageRenderer.java:233)
	at org.apache.wicket.core.request.handler.RenderPageRequestHandler.respond(RenderPageRequestHandler.java:175)
	at org.apache.wicket.request.cycle.RequestCycle$HandlerExecutor.respond(RequestCycle.java:891)
	at org.apache.wicket.request.RequestHandlerStack.execute(RequestHandlerStack.java:64)
	at org.apache.wicket.request.cycle.RequestCycle.execute(RequestCycle.java:260)
	at org.apache.wicket.request.cycle.RequestCycle.processRequest(RequestCycle.java:217)
	at org.apache.wicket.request.cycle.RequestCycle.processRequestAndDetach(RequestCycle.java:288)
	at org.apache.wicket.protocol.ws.AbstractUpgradeFilter.processRequestCycle(AbstractUpgradeFilter.java:70)
	at org.apache.wicket.protocol.http.WicketFilter.processRequest(WicketFilter.java:203)
	at org.apache.wicket.protocol.http.WicketServlet.doGet(WicketServlet.java:137)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
	at io.onedev.server.web.DefaultWicketServlet.lambda$service$0(DefaultWicketServlet.java:45)
	at io.onedev.server.persistence.DefaultSessionManager.lambda$run$0(DefaultSessionManager.java:108)
	at io.onedev.server.persistence.DefaultSessionManager.call(DefaultSessionManager.java:90)
	at io.onedev.server.persistence.DefaultSessionManager.run(DefaultSessionManager.java:107)
	at io.onedev.server.web.DefaultWicketServlet.service(DefaultWicketServlet.java:42)
	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:799)
	at org.eclipse.jetty.servlet.ServletHandler$ChainEnd.doFilter(ServletHandler.java:1656)
	at com.google.inject.servlet.DefaultFilterPipeline.dispatch(DefaultFilterPipeline.java:47)
	at com.google.inject.servlet.GuiceFilter.doFilter(GuiceFilter.java:133)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1626)
	at io.onedev.server.git.GoGetFilter.doFilter(GoGetFilter.java:87)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1626)
	at io.onedev.server.git.GitLfsFilter.doFilter(GitLfsFilter.java:454)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1626)
	at io.onedev.server.git.GitFilter.doFilter(GitFilter.java:363)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1626)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:61)
	at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
	at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:154)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
	at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
	at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:154)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
	at org.apache.shiro.web.servlet.AdviceFilter.executeChain(AdviceFilter.java:108)
	at org.apache.shiro.web.servlet.AdviceFilter.doFilterInternal(AdviceFilter.java:137)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:154)
	at org.apache.shiro.web.servlet.ProxiedFilterChain.doFilter(ProxiedFilterChain.java:66)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.executeChain(AbstractShiroFilter.java:458)
	at org.apache.shiro.web.servlet.AbstractShiroFilter$1.call(AbstractShiroFilter.java:373)
	at org.apache.shiro.subject.support.SubjectCallable.doCall(SubjectCallable.java:90)
	at org.apache.shiro.subject.support.SubjectCallable.call(SubjectCallable.java:83)
	at org.apache.shiro.subject.support.DelegatingSubject.execute(DelegatingSubject.java:387)
	at org.apache.shiro.web.servlet.AbstractShiroFilter.doFilterInternal(AbstractShiroFilter.java:370)
	at org.apache.shiro.web.servlet.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:154)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1626)
	at io.onedev.server.security.CorsFilter.doFilter(CorsFilter.java:47)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1626)
	at io.onedev.server.jetty.DisableTraceFilter.doFilter(DisableTraceFilter.java:28)
	at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:193)
	at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1626)
	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:552)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1624)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:233)
	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1440)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:188)
	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:505)
	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1594)
	at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:186)
	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1355)
	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
	at org.eclipse.jetty.server.handler.gzip.GzipHandler.handle(GzipHandler.java:772)
	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:127)
	at org.eclipse.jetty.server.Server.handle(Server.java:516)
	at org.eclipse.jetty.server.HttpChannel.lambda$handle$1(HttpChannel.java:487)
	at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:732)
	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:479)
	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:277)
	at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:311)
	at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:105)
	at org.eclipse.jetty.io.ChannelEndPoint$1.run(ChannelEndPoint.java:104)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.runTask(EatWhatYouKill.java:338)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.doProduce(EatWhatYouKill.java:315)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.tryProduce(EatWhatYouKill.java:173)
	at org.eclipse.jetty.util.thread.strategy.EatWhatYouKill.run(EatWhatYouKill.java:131)
	at org.eclipse.jetty.util.thread.ReservedThreadExecutor$ReservedThread.run(ReservedThreadExecutor.java:409)
	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:883)
	at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1034)
	at java.base/java.lang.Thread.run(Thread.java:829)