in cdk-stacks/configure.js [111:122]
function checkRequiredParameters() {
    for (const param of configParams.parameters) {
        if (param.required && !param.parent && isNotDefined(param)) {
            throwParameterRequired(param)
        }
        if (param.required && param.parent && isParentEnabled(param) && isNotDefined(param)) {
            throwParameterRequired(param)
        }
    }
}