private boolean isAvailable(String command) {
    MethodTarget target = availabilityIndicators.get(command);
    if (target == null) {
      return true;
    }
    try {
      return (Boolean) target.getMethod().invoke(target.getTarget());
    } catch (Exception e) {
      return false;
    }
  }
get help string for a specific command, or a brief description of all the commands if buffer is
null or empty
geode-gfsh/src/main/java/org/apache/geode/management/internal/cli/help/Helper.java