public function setMasteryValue($masteryValue)
    {
        if ((is_bool($masteryValue) && $masteryValue === false) || is_float($masteryValue) || is_double($masteryValue)) {
            $this->masteryValue = $masteryValue;
        } else {
            $msg = "The masteryValue argument must be a floating point value or false, '" . gettype($masteryValue) . "' given.";
            throw new InvalidArgumentException($msg);
        }
    }