manual('engineering') {
                                                                 parameters{
-                                                                    textParam 'SOURCE'
+                                                                    validatingStringParameterDefinition {
+                                                                        name 'SOURCE'
+                                                                        regex '^[0-9]+$'
+                                                                        defaultValue ''
+                                                                        failedValidationMessage ''
+                                                                        description 'Commit to be merged into integration branch'
+                                                                    }
                                                                 }
                                                             }

java.lang.ClassCastException: java.lang.String cannot be cast to groovy.util.Node
	at hudson.plugins.promoted_builds.integrations.jobdsl.ManualConditionConverter.convertNode(ManualConditionConverter.java:63)
	at hudson.plugins.promoted_builds.integrations.jobdsl.ManualConditionConverter.marshal(ManualConditionConverter.java:48)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:69)
	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:58)
	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:43)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:88)
	at com.thoughtworks.xstream.converters.collections.AbstractCollectionConverter.writeItem(AbstractCollectionConverter.java:64)
	at com.thoughtworks.xstream.converters.collections.CollectionConverter.marshal(CollectionConverter.java:74)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:69)
	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:58)
	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:43)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller$1.convertAnother(AbstractReferenceMarshaller.java:88)
	at hudson.plugins.promoted_builds.integrations.jobdsl.JobDslPromotionProcessConverter.marshal(JobDslPromotionProcessConverter.java:73)
	at com.thoughtworks.xstream.core.AbstractReferenceMarshaller.convert(AbstractReferenceMarshaller.java:69)
	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:58)
	at com.thoughtworks.xstream.core.TreeMarshaller.convertAnother(TreeMarshaller.java:43)
	at com.thoughtworks.xstream.core.TreeMarshaller.start(TreeMarshaller.java:82)
	at com.thoughtworks.xstream.core.AbstractTreeMarshallingStrategy.marshal(AbstractTreeMarshallingStrategy.java:37)
	at com.thoughtworks.xstream.XStream.marshal(XStream.java:1026)
	at com.thoughtworks.xstream.XStream.marshal(XStream.java:1015)
	at com.thoughtworks.xstream.XStream.toXML(XStream.java:988)
	at com.thoughtworks.xstream.XStream.toXML(XStream.java:975)
	at hudson.plugins.promoted_builds.integrations.jobdsl.PromotionsExtensionPoint.notifyItemCreated(PromotionsExtensionPoint.java:78)
	at hudson.plugins.promoted_builds.integrations.jobdsl.PromotionsExtensionPoint.notifyItemUpdated(PromotionsExtensionPoint.java:136)
	at javaposse.jobdsl.plugin.JenkinsJobManagement.notifyItemUpdated(JenkinsJobManagement.java:575)
	at javaposse.jobdsl.plugin.JenkinsJobManagement.updateExistingItem(JenkinsJobManagement.java:501)
	at javaposse.jobdsl.plugin.JenkinsJobManagement.createOrUpdateConfig(JenkinsJobManagement.java:149)
	at javaposse.jobdsl.dsl.JobManagement$createOrUpdateConfig$10.call(Unknown Source)
	at javaposse.jobdsl.plugin.InterruptibleJobManagement.createOrUpdateConfig(InterruptibleJobManagement.groovy:37)
	at javaposse.jobdsl.dsl.JobManagement$createOrUpdateConfig$10.call(Unknown Source)
	at javaposse.jobdsl.dsl.AbstractDslScriptLoader$_extractGeneratedJobs_closure4.doCall(AbstractDslScriptLoader.groovy:187)
	at sun.reflect.GeneratedMethodAccessor9651.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
	at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
	at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:294)
	at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
	at groovy.lang.Closure.call(Closure.java:414)
	at groovy.lang.Closure.call(Closure.java:430)
	at org.codehaus.groovy.runtime.DefaultGroovyMethods.each(DefaultGroovyMethods.java:2030)
	at org.codehaus.groovy.runtime.DefaultGroovyMethods.each(DefaultGroovyMethods.java:2015)
	at org.codehaus.groovy.runtime.DefaultGroovyMethods.each(DefaultGroovyMethods.java:2056)
	at org.codehaus.groovy.runtime.dgm$162.invoke(Unknown Source)
	at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoMetaMethodSiteNoUnwrapNoCoerce.invoke(PojoMetaMethodSite.java:274)
	at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:56)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:125)
	at javaposse.jobdsl.dsl.AbstractDslScriptLoader.extractGeneratedJobs(AbstractDslScriptLoader.groovy:180)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite$PogoCachedMethodSiteNoUnwrapNoCoerce.invoke(PogoMetaMethodSite.java:210)
	at org.codehaus.groovy.runtime.callsite.PogoMetaMethodSite.callCurrent(PogoMetaMethodSite.java:59)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:174)
	at javaposse.jobdsl.dsl.AbstractDslScriptLoader.extractGeneratedItems(AbstractDslScriptLoader.groovy:167)
	at javaposse.jobdsl.plugin.JenkinsDslScriptLoader.extractGeneratedItems(JenkinsDslScriptLoader.java:23)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
	at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
	at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:384)
	at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
	at org.codehaus.groovy.runtime.callsite.PogoMetaClassSite.callCurrent(PogoMetaClassSite.java:69)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.callCurrent(AbstractCallSite.java:182)
	at javaposse.jobdsl.dsl.AbstractDslScriptLoader$_runScripts_closure1.doCall(AbstractDslScriptLoader.groovy:60)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:93)
	at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:325)
	at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:294)
	at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1024)
	at groovy.lang.Closure.call(Closure.java:414)
	at groovy.lang.Closure.call(Closure.java:430)
	at org.codehaus.groovy.runtime.DefaultGroovyMethods.each(DefaultGroovyMethods.java:2030)
	at org.codehaus.groovy.runtime.DefaultGroovyMethods.each(DefaultGroovyMethods.java:2015)
	at org.codehaus.groovy.runtime.DefaultGroovyMethods.each(DefaultGroovyMethods.java:2068)
	at org.codehaus.groovy.runtime.dgm$164.invoke(Unknown Source)
	at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite$PojoMetaMethodSiteNoUnwrapNoCoerce.invoke(PojoMetaMethodSite.java:274)
	at org.codehaus.groovy.runtime.callsite.PojoMetaMethodSite.call(PojoMetaMethodSite.java:56)
	at org.codehaus.groovy.runtime.callsite.AbstractCallSite.call(AbstractCallSite.java:125)
	at javaposse.jobdsl.dsl.AbstractDslScriptLoader.runScripts(AbstractDslScriptLoader.groovy:45)
	at javaposse.jobdsl.plugin.ExecuteDslScripts.perform(ExecuteDslScripts.java:251)
	at hudson.tasks.BuildStepCompatibilityLayer.perform(BuildStepCompatibilityLayer.java:78)
	at hudson.tasks.BuildStepMonitor$1.perform(BuildStepMonitor.java:20)
	at hudson.model.AbstractBuild$AbstractBuildExecution.perform(AbstractBuild.java:779)
	at hudson.model.Build$BuildExecution.build(Build.java:206)
	at hudson.model.Build$BuildExecution.doRun(Build.java:163)
	at hudson.model.AbstractBuild$AbstractBuildExecution.run(AbstractBuild.java:534)
	at hudson.model.Run.execute(Run.java:1728)
	at hudson.model.FreeStyleBuild.run(FreeStyleBuild.java:43)
	at hudson.model.ResourceController.execute(ResourceController.java:98)
	at hudson.model.Executor.run(Executor.java:405)
ERROR: java.lang.String cannot be cast to groovy.util.Node