@Override
  public void validate(ClusterTopology topology) throws InvalidTopologyException {
    for (TopologyValidator validator : validators) {
      LOGGER.info("Performing topology validation: {}", validator.getClass());
      validator.validate(topology);
    }
  }
Topology validator wrapper implementation. Executes a set of validations by calling a preconfgured set of validator implementations.
ambari-server/src/main/java/org/apache/ambari/server/topology/validators/ChainedTopologyValidator.java