private static void ensureProperty(Configuration configuration, String type, String property, String defaultValue, Set<String> configTypesUpdated) {
    if (configuration.getPropertyValue(type, property) == null) {
      configuration.setProperty(type, property, defaultValue);
      configTypesUpdated.add(type);
    }
  }
Ensure that the specified property exists.
If not, set a default value.

@param configuration  configuration being processed
@param type           config type
@param property       property name
@param defaultValue   default value
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/BlueprintConfigurationProcessor.java