src/Extensions/ContentReviewCMSExtension.php
public function ReviewContentForm(HTTPRequest $request)
    {
        // Get ID either from posted back value, or url parameter
        $id = $request->param('ID') ?: $request->postVar('ID');
        return $this->getReviewContentForm($id);
    }
public function ReviewContentForm(HTTPRequest $request)
    {
        // Get ID either from posted back value, or url parameter
        $id = $request->param('ID') ?: $request->postVar('ID');
        return $this->getReviewContentForm($id);
    }
URL handler for the "content due for review" form

@param HTTPRequest $request
@return Form|null