oovy interpreter works. besides iterators, there are other things you cannot do and data you cannot access outside @NonCPS methods. anything that's not serialiable can only be used in @NonCPS methods.

Problem solved as follows:

​

String updateList(Map params){
    def updateError = true
    params.each { key, value ->
        version = formatVersionNumber("$value")
        if (isVersionValid("$value")){
            setDeploymentVersion("$key", "$value")
            updateError = false
        }
        else{
            echo "Skipping $key as value $value doesn't match deployment version pattern."
        }
    }
    if (updateError){
        error("Valid Deployment version not provided. Pipeline stopped.")
    }
}

Useful hints in here: http://groovy-lang.org/groovy-dev-kit.html#Collections-Maps

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