    function setCACertificate($caFile)
    {
        if (is_file($caFile)) {
            $this->_caFile = $caFile;
        } else {
            throw new ClientException('Could not open CA certificate: ' . $caFile);
        }
    }
The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.