protected String getValue(AmbariServerConfigurationKey ambariServerConfigurationKey, Map<String, String> configurationMap) {
    return getValue(ambariServerConfigurationKey.key(), configurationMap, ambariServerConfigurationKey.getDefaultValue());
  }
Gets the configuration value for given {@link AmbariServerConfigurationKey}.
<p>
If no value is found in the supplied configuration map, the default value will be returned.

@param ambariServerConfigurationKey the {@link AmbariServerConfigurationKey} for which to retrieve a value
@param configurationMap             a map of configuration property names to values
@return the requested configuration value
ambari-server/src/main/java/org/apache/ambari/server/configuration/AmbariServerConfiguration.java