public function push(Relational $model)
	{
		// Index by primary key if possible, otherwise plain incremental array
		// Also check to see if that key already exists.  If so, we'll just start
		// appending items to the array.  This will result in a mixed array and
		// subsequent items will not be seekable.
		if ($model->getPkValue() && (!is_array($this->rows) || !array_key_exists($model->getPkValue(), $this->rows)))
		{
			$this->rows[$model->getPkValue()] = $model;
		}
		else
		{
			$this->rows[] = $model;
		}
	}