private void mergeConfiguration(Map<String, Map<String, String>> configurations,
                                  String configurationSpecification,
                                  String value,
                                  Map<String, Map<String, String>> replacements) throws AmbariException {

    if (configurationSpecification != null) {
      String[] parts = configurationSpecification.split("/");
      if (parts.length == 2) {
        String type = parts[0];
        String property = parts[1];

        mergeConfigurations(configurations, type, Collections.singletonMap(property, value), replacements);
      }
    }
  }
Merges the specified configuration property in a map of configuration types.
The supplied property is processed to replace variables using the replacement Map.
<p/>
See {@link VariableReplacementHelper#replaceVariables(String, java.util.Map)}
for information on variable replacement.

@param configurations             the Map of configuration types to update
@param configurationSpecification the config-type/property_name value specifying the property to set
@param value                      the value of the property to set
@param replacements               a Map of (grouped) replacement values
@throws AmbariException
ambari-server/src/main/java/org/apache/ambari/server/controller/KerberosHelperImpl.java