code: public static void checkArgument(boolean validCondition, String argName, String message, Object... args) throws IllegalArgumentException {
          if (!validCondition) {
              throw new IllegalArgumentException(badArgumentMessage(argName, message, args));
          }
      }
docs: Throws an IllegalArgumentException if the validCondition argument is false.
  
  @param validCondition The result of the condition to validate.
  @param argName        The name of the argument (to be included in the exception message).
  @param message        The message to include in the exception. This should not include the name of the argument,
  as that is already prefixed.
  @param args           Format args for message. These must correspond to String.format() args.
  @throws IllegalArgumentException If validCondition is false.