private function doInsert($model, $fields, $returnId)
    {
        return $model::objects()->_insert($this, $fields, $returnId);
    }
private function doInsert($model, $fields, $returnId)
    {
        return $model::objects()->_insert($this, $fields, $returnId);
    }
private function doInsert ( $ model , $ fields , $ returnId ) { return $ model :: objects ( ) -> _insert ( $ this , $ fields , $ returnId ) ; }
Do an INSERT. If update_pk is defined then this method should return
the new pk for the model.

@param Model   $model
@param Field[] $fields   fields that are on this model
@param         $returnId

@return mixed

@since  1.1.0

@author Eddilbert Macharia (http://eddmash.com) <edd.cowan@gmail.com>
Do an INSERT . If update_pk is defined then this method should return the new pk for the model .