private bool CheckDocumentPermissions()
{
    // Create an instance of the Tree provider
    TreeProvider tree = new TreeProvider(CMSContext.CurrentUser);

    // Get default culture code
    string culture = SettingsKeyProvider.GetStringValue(CMSContext.CurrentSiteName + ".CMSDefaultCultureCode");

    // Get the API Example document
    TreeNode node = tree.SelectSingleNode(CMSContext.CurrentSiteName, "/API-Example", culture);

    if (node != null)
    {
        // Get the user
        UserInfo user = UserInfoProvider.GetUserInfo("Andy");

        if (user != null)
        {
            // Check permissions and perform an action according to the result
            if (TreeSecurityProvider.IsAuthorizedPerNode(node, NodePermissionsEnum.ModifyPermissions, user) == AuthorizationResultEnum.Allowed)
            {
                apiCheckDocumentPermissions.InfoMessage = "User 'Andy' is allowed to modify permissions for document 'API Example'.";
            }
            else
            {
                apiCheckDocumentPermissions.InfoMessage = "User 'Andy' is not allowed to modify permissions for document 'API Example'.";
            }

            return true;
        }
    }

    return false;
}