src/Extensions/ContentReviewCMSExtension.php
protected function findRecord($data)
    {
        if (empty($data["ID"])) {
            throw new HTTPResponse_Exception("No record ID", 404);
        }
        $page = null;
        $id = $data["ID"];
        if (is_numeric($id)) {
            $page = SiteTree::get()->byID($id);
        }
        if (!$page || !$page->ID) {
            throw new HTTPResponse_Exception("Bad record ID #{$id}", 404);
        }
        return $page;
    }
protected function findRecord($data)
    {
        if (empty($data["ID"])) {
            throw new HTTPResponse_Exception("No record ID", 404);
        }
        $page = null;
        $id = $data["ID"];
        if (is_numeric($id)) {
            $page = SiteTree::get()->byID($id);
        }
        if (!$page || !$page->ID) {
            throw new HTTPResponse_Exception("Bad record ID #{$id}", 404);
        }
        return $page;
    }
Find the page this form is updating

@param array $data Form data
@return SiteTree Record
@throws HTTPResponse_Exception