private static boolean propertyHasCustomValue(Map<String, String> clusterConfigProperties, Map<String, String> stackDefaultConfigProperties, String property) {

    boolean propertyHasCustomValue = false;
    if (clusterConfigProperties != null) {
      String propertyValue = clusterConfigProperties.get(property);
      if (propertyValue != null) {
        if (stackDefaultConfigProperties != null) {
          String stackDefaultValue = stackDefaultConfigProperties.get(property);
          if (stackDefaultValue != null) {
            propertyHasCustomValue = !propertyValue.equals(stackDefaultValue);
          } else {
            propertyHasCustomValue = true;
          }
        } else {
          propertyHasCustomValue = true;
        }
      }
    }
    return propertyHasCustomValue;
  }
Returns true if the property exists in clusterConfigProperties and has a custom user defined value. Property has
custom value in case we there's no stack default value for it or it's not equal to stack default value.
ambari-server/src/main/java/org/apache/ambari/server/topology/Configuration.java