public Distribution createDistribution(SlobrokPolicy policy) {
            return distributionConfig == null ? new Distribution(getDistributionConfigId())
                                              : new Distribution(distributionConfig.cluster(clusterName));
        }
Class parsing the semicolon separated parameter string and exposes the appropriate value to the policy.
documentapi/src/main/java/com/yahoo/documentapi/messagebus/protocol/ContentPolicy.java