public function fileopsCopy($fromPath = null, $toPath, $fromCopyRef = null, $locale = null, $sandbox = false)
        {
            // build url
            $url = '1/fileops/copy';

            // build parameters
            $parameters['root'] = ($sandbox) ? 'sandbox' : 'dropbox';
            if($fromPath !== null) $parameters['from_path'] = (string) $fromPath;
            $parameters['to_path'] = (string) $toPath;
            if($fromCopyRef !== null) $parameters['from_copy_ref'] = (string) $fromCopyRef;
            if($locale !== null) $parameters['locale'] = (string) $locale;

            // make the call
            return $this->doCall($url, $parameters, 'POST');
        }