Playground doesn't import hudson

[saxonww]

I have a couple of DSL scripts where I need to use hudson.util.Secret.fromString(). When I try to validate these in the playground, I get an exception, e.g.:

javaposse.jobdsl.dsl.DslScriptException: (script, line 68) No such property: hudson for class: script
at javaposse.jobdsl.dsl.DslScriptLoader.runDslEngineForParent(DslScriptLoader.java:79)
at javaposse.jobdsl.dsl.DslScriptLoader.runDslEngine(DslScriptLoader.java:135)
at javaposse.jobdsl.dsl.DslScriptLoader$runDslEngine.call(Unknown Source)
at com.sheehan.jobdsl.DslScriptExecutor.execute(DslScriptExecutor.groovy:29)
at com.sheehan.jobdsl.ScriptExecutor$execute.call(Unknown Source)
at Ratpack$_run_closure1_closure3_closure7.doCall(Ratpack.groovy:39)
at ratpack.groovy.internal.ClosureInvoker.invoke(ClosureInvoker.java:65)
at ratpack.groovy.handling.internal.ClosureBackedHandler.handle(ClosureBackedHandler.java:42)
at ratpack.handling.internal.DefaultContext.doNext(DefaultContext.java:448)
at ratpack.handling.internal.DefaultContext.next(DefaultContext.java:223)
at ratpack.http.internal.MethodHandler.handle(MethodHandler.java:41)
at ratpack.handling.internal.DefaultContext.doNext(DefaultContext.java:448)
at ratpack.handling.internal.DefaultContext.insert(DefaultContext.java:237)
at ratpack.handling.internal.ChainHandler.handle(ChainHandler.java:37)
at ratpack.handling.internal.DefaultContext.doNext(DefaultContext.java:448)
at ratpack.handling.internal.DefaultContext.insert(DefaultContext.java:246)
at ratpack.path.internal.PathHandler.handle(PathHandler.java:38)
at ratpack.handling.internal.DefaultContext.doNext(DefaultContext.java:448)
at ratpack.handling.internal.DefaultContext.next(DefaultContext.java:223)
at ratpack.path.internal.PathHandler.handle(PathHandler.java:40)
at ratpack.handling.internal.DefaultContext.doNext(DefaultContext.java:448)
at ratpack.handling.internal.DefaultContext.next(DefaultContext.java:223)
at ratpack.path.internal.PathHandler.handle(PathHandler.java:40)
at ratpack.handling.internal.DefaultContext.doNext(DefaultContext.java:448)
at ratpack.handling.internal.DefaultContext.insert(DefaultContext.java:237)
at ratpack.handling.internal.ChainHandler.handle(ChainHandler.java:37)
at ratpack.handling.internal.DefaultContext.doNext(DefaultContext.java:448)
at ratpack.handling.internal.DefaultContext.insert(DefaultContext.java:237)
at ratpack.handling.internal.ChainHandler.handle(ChainHandler.java:37)
at ratpack.handling.internal.DefaultContext.doNext(DefaultContext.java:448)
at ratpack.handling.internal.DefaultContext.insert(DefaultContext.java:246)
at ratpack.guice.internal.InjectorBindingHandler.handle(InjectorBindingHandler.java:36)
at ratpack.groovy.internal.ScriptBackedApp.handle(ScriptBackedApp.java:97)
at ratpack.handling.internal.DefaultContext.doNext(DefaultContext.java:448)
at ratpack.handling.internal.DefaultContext.next(DefaultContext.java:223)
at ratpack.handling.internal.DefaultContext$2.execute(DefaultContext.java:127)
at ratpack.handling.internal.DefaultContext$2.execute(DefaultContext.java:124)
at ratpack.exec.internal.ExecutionBacking$3.performOperation(ExecutionBacking.java:174)
at ratpack.handling.internal.InterceptedOperation.run(InterceptedOperation.java:43)
at ratpack.exec.internal.ExecutionBacking.intercept(ExecutionBacking.java:171)
at ratpack.exec.internal.ExecutionBacking$UserCodeSegment.run(ExecutionBacking.java:189)
at ratpack.exec.internal.ExecutionBacking.drain(ExecutionBacking.java:136)
at ratpack.exec.internal.ExecutionBacking.tryDrain(ExecutionBacking.java:108)
at ratpack.exec.internal.ExecutionBacking.(ExecutionBacking.java:61)
at ratpack.exec.internal.DefaultExecControl.fork(DefaultExecControl.java:151)
at ratpack.handling.internal.DefaultContext.start(DefaultContext.java:124)
at ratpack.server.internal.NettyHandlerAdapter.channelRead0(NettyHandlerAdapter.java:191)
at ratpack.server.internal.NettyHandlerAdapter.channelRead0(NettyHandlerAdapter.java:80)
at io.netty.channel.SimpleChannelInboundHandler.channelRead(SimpleChannelInboundHandler.java:103)
at ratpack.server.internal.NettyHandlerAdapter.channelRead(NettyHandlerAdapter.java:127)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:332)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:318)
at io.netty.channel.ChannelInboundHandlerAdapter.channelRead(ChannelInboundHandlerAdapter.java:86)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:332)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:318)
at io.netty.handler.codec.MessageToMessageDecoder.channelRead(MessageToMessageDecoder.java:103)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:332)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:318)
at io.netty.handler.codec.ByteToMessageDecoder.channelRead(ByteToMessageDecoder.java:163)
at io.netty.channel.AbstractChannelHandlerContext.invokeChannelRead(AbstractChannelHandlerContext.java:332)
at io.netty.channel.AbstractChannelHandlerContext.fireChannelRead(AbstractChannelHandlerContext.java:318)
at io.netty.channel.DefaultChannelPipeline.fireChannelRead(DefaultChannelPipeline.java:787)
at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:125)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:507)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:464)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:378)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:350)
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:116)
at ratpack.exec.internal.DefaultExecController$ExecControllerBindingThreadFactory$1.run(DefaultExecController.java:90)
Caused by: groovy.lang.MissingPropertyException: No such property: hudson for class: script
at script.run(script:68)
at javaposse.jobdsl.dsl.DslScriptLoader.runDslEngineForParent(DslScriptLoader.java:75)
... 68 more