code: protected void promptRequiredMissingValues(ShellImpl shell, Iterable<InputComponent<?, ?>> inputs)
              throws InterruptedException
     {
        ShellUIPromptImpl prompt = shell.createPrompt(context);
        for (InputComponent<?, ?> input : inputs)
        {
           if (input.isEnabled() && !input.isDeprecated())
           {
              boolean requiredInputMissing = input.isRequired() && !(input.hasDefaultValue() || input.hasValue());
              Object obj = prompt.promptValueFrom(input);
              if (obj == null && requiredInputMissing)
              {
                 // No value returned. Just stop testing other inputs
                 break;
              }
           }
        }
  
     }
docs: Called by {@link AbstractShellInteraction#promptRequiredMissingValues(ShellImpl)}