public RepositoryVersion getServiceRepositoryVersion(String serviceName) {
    return m_serviceVersions.get(serviceName);
  }
Gets the {@link RepositoryVersion} for the given service which represents
the service's current version in the cluster.

@param serviceName
         the service name.
@return the repository version information for the given service.
ambari-server-spi/src/main/java/org/apache/ambari/spi/ClusterInformation.java