getExpectedValue = argConfig => {
	switch (argConfig.type) {
		case "boolean":
			return "true | false";
		case "RegExp":
			return "regular expression (example: /ab?c*/)";
		case "enum":
			return /** @type {NonNullable<ArgumentConfig["values"]>} */ (
				argConfig.values
			)
				.map(v => `${v}`)
				.join(" | ");
		case "reset":
			return "true (will reset the previous value to an empty array)";
		default:
			return argConfig.type;
	}
}
@param {ArgumentConfig} argConfig processing instructions
@returns {string | undefined} expected message