@Override
      public Role apply(HostRoleCommand hrc) {
        return hrc.getRole();
      }
Get all {@link Role} any of whose tasks are in given {@code status}
@param hostRoleCommands list of {@link HostRoleCommand}
@param status {@link HostRoleStatus}
@return Set of {@link Role}
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/CalculatedStatus.java