code: private static String checkValueIsNotAnArg(String argument, String value) {
          if (value.startsWith("-")) {
              STDERR.println(HostControllerLogger.ROOT_LOGGER.argumentHasNoValue(argument, usageNote()));
              return null;
          }
          return value;
      }
docs: Validates that param {@code value} does not begin with the character {@code -}. For use in cases where
  the legal value for an argument would not begin with that character. Usage is to detect missing argument
  values, where the command line includes another argument instead of the value for the last argument.
  
  @param argument the last argument, whose value should be {@code value}
  @param value the next item in the command line arguments, which should be the value for {@code argument}
  @return  {@code value} if it is valid, or {@code null} if it is not