kernel/private/rest/classes/controllers/rest_controller.php
protected function getContentVariable( $name )
    {
        if ( isset( $this->request->contentVariables[$name] ) )
        {
            return $this->request->contentVariables[$name];
        }

        return null;
    }
protected function getContentVariable( $name )
    {
        if ( isset( $this->request->contentVariables[$name] ) )
        {
            return $this->request->contentVariables[$name];
        }

        return null;
    }
protected function getContentVariable ( $ name ) { if ( isset ( $ this -> request -> contentVariables [ $ name ] ) ) { return $ this -> request -> contentVariables [ $ name ] ; } return null ; }
Returns requested content variable, is it set

@param string $name Content variable name

@return string|null
Returns requested content variable is it set