function callSyncFirstHook (container, hook, args) {
    let plugins = _getSortedPlugins(container.__plugins, hook);

    // waits for hook to return value other than null of undefined
    for (let i = 0; i < plugins.length; i++) {
        let hr = _callSyncHook(plugins[i], hook, args);

        if (hr !== null && hr !== undefined) {
            return hr;
        }
    } 
}
@param {PluginContainer} container 
@param {string} hook 
@param {any[]} args 
@return {any}