private void removeConfigurationTypes(Cluster cluster, Set<String> configurationTypeRemovals)
      throws AmbariException {
    if (null == configurationTypeRemovals) {
      return;
    }

    for (String configType : configurationTypeRemovals) {
      m_configHelper.removeConfigsByType(cluster, configType);
    }
  }
Remove the specified configuration types from the cluster.

@param cluster
         the cluster to remove the configurations from.
@param configurationTypeRemovals
         the types to remove.
@throws AmbariException
          if there were problems removing the configuration types.
ambari-server/src/main/java/org/apache/ambari/server/serveraction/upgrades/PluginUpgradeServerAction.java