Locker\Repository\Statement\Options::validate PHP Method

    protected function validate($opts)
    {
        foreach ($opts as $key => $value) {
            if ($value !== null && isset($this->types[$key]) && $this->types[$key] !== null) {
                if (is_array($this->types[$key])) {
                    $class = '\\Locker\\XApi\\' . $this->types[$key][0];
                    if (!is_array($value)) {
                        throw new Exceptions\Exception("{$key} must be an array.");
                    }
                    foreach ($value as $item) {
                        Helpers::validateAtom(new $class($item));
                    }
                } else {
                    $class = '\\Locker\\XApi\\' . $this->types[$key];
                    Helpers::validateAtom(new $class($value));
                }
            }
        }
        return $opts;
    }

 /**
  * Validates the given options as index options.
  * @param [String => Mixed] $opts
  * @return [String => Mixed]
  */
 protected function validate($opts)
 {
     $opts = parent::validate($opts);
     // Validates values.
     if (!isset($opts['lrs_id'])) {
         throw new Exceptions\Exception('`lrs_id` must be set.');
     }
     if ($opts['offset'] < 0) {
         throw new Exceptions\Exception('`offset` must be a positive interger.');
     }
     if ($opts['limit'] < 1) {
         throw new Exceptions\Exception('`limit` must be a positive interger.');
     }
     if (!in_array($opts['format'], ['exact', 'canonical', 'ids'])) {
         throw new Exceptions\Exception('`format` must be "exact", "canonical", or "ids".');
     }
     return $opts;
 }