java.lang.NullPointerException
	at org.jenkinsci.plugins.workflow.cps.persistence.IteratorHack.writeReplace(IteratorHack.java:52)
	at org.jenkinsci.plugins.workflow.cps.ParamsVariable.addValue(ParamsVariable.java:88)
	at org.jenkinsci.plugins.workflow.cps.ParamsVariable.getValue(ParamsVariable.java:66)
	at org.jenkinsci.plugins.workflow.cps.CpsScript.getProperty(CpsScript.java:121)
	at org.codehaus.groovy.runtime.InvokerHelper.getProperty(InvokerHelper.java:174)
	at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.getProperty(ScriptBytecodeAdapter.java:456)
	at org.kohsuke.groovy.sandbox.impl.Checker$4.call(Checker.java:243)
	at org.kohsuke.groovy.sandbox.GroovyInterceptor.onGetProperty(GroovyInterceptor.java:52)
	at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onGetProperty(SandboxInterceptor.java:308)
	at org.kohsuke.groovy.sandbox.impl.Checker$4.call(Checker.java:241)
	at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:238)
	at com.cloudbees.groovy.cps.sandbox.SandboxInvoker.getProperty(SandboxInvoker.java:28)
	at com.cloudbees.groovy.cps.impl.PropertyAccessBlock.rawGet(PropertyAccessBlock.java:20)
	at Script1.checkParameters(Script1.groovy:469)
	at Script1.runPipeline(Script1.groovy:84)
	at ___cps.transform___(Native Method)
	at com.cloudbees.groovy.cps.impl.PropertyishBlock$ContinuationImpl.get(PropertyishBlock.java:74)
	at com.cloudbees.groovy.cps.LValueBlock$GetAdapter.receive(LValueBlock.java:30)
	at com.cloudbees.groovy.cps.impl.PropertyishBlock$ContinuationImpl.fixName(PropertyishBlock.java:66)
	at sun.reflect.GeneratedMethodAccessor467.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at com.cloudbees.groovy.cps.impl.ContinuationPtr$ContinuationImpl.receive(ContinuationPtr.java:72)
	at com.cloudbees.groovy.cps.impl.ConstantBlock.eval(ConstantBlock.java:21)
	at com.cloudbees.groovy.cps.Next.step(Next.java:74)
	at com.cloudbees.groovy.cps.Continuable.run0(Continuable.java:154)
	at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.access$001(SandboxContinuable.java:18)
	at org.jenkinsci.plugins.workflow.cps.SandboxContinuable$1.call(SandboxContinuable.java:33)
	at org.jenkinsci.plugins.workflow.cps.SandboxContinuable$1.call(SandboxContinuable.java:30)
	at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.GroovySandbox.runInSandbox(GroovySandbox.java:108)
	at org.jenkinsci.plugins.workflow.cps.SandboxContinuable.run0(SandboxContinuable.java:30)
	at org.jenkinsci.plugins.workflow.cps.CpsThread.runNextChunk(CpsThread.java:165)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.run(CpsThreadGroup.java:328)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup.access$100(CpsThreadGroup.java:80)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:240)
	at org.jenkinsci.plugins.workflow.cps.CpsThreadGroup$2.call(CpsThreadGroup.java:228)
	at org.jenkinsci.plugins.workflow.cps.CpsVmExecutorService$2.call(CpsVmExecutorService.java:64)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at hudson.remoting.SingleLaneExecutorService$1.run(SingleLaneExecutorService.java:112)
	at jenkins.util.ContextResettingExecutorService$1.run(ContextResettingExecutorService.java:28)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at java.lang.Thread.run(Thread.java:745)