protected function configToolProvider(ConfigXML $config)
    {
        $handlers = $config->toArray('/config/tool/handlers')[0];
        if (empty($handlers) || !is_array($handlers)) {
            throw new ConfigurationException(
                'At least one handler/URL pair must be specified',
                ConfigurationException::TOOL_PROVIDER
            );
        }
        foreach ($handlers as $request => $path) {
            $handlers[$request] = DataUtilities::URLfromPath(
                dirname($this->config(static::TOOL_CONFIG_FILE)) . "/$path"
            );
        }
        $this->config(static::TOOL_HANDLER_URLS, $handlers);
        $this->log('Tool provider handler URLs configured');
    }