public List<ExecutionCommandWrapper> getExecutionCommands(String hostname) {
    checkWrappersLoaded();
    return commandsToSend.get(getSafeHost(hostname));
  }
@param hostname    the hostname; {@code null} for a server-side stage
@return  the list of commands for the host
ambari-server/src/main/java/org/apache/ambari/server/actionmanager/Stage.java