Custom Select Rows

Hello, i am changing the gridOption.data values according to a Custom Search functionality i apply to the Grid. The selected Rows, of the previous searches, i save them in an object. But in the new Rows that are comming from the Search, i want to be selected in the grid, those who are available in the Object i use to store previous rows.

I have found the $scope.gridApi.selection.selectRow($row_entity), but this works for a single Row. I want to select more than One. Is there a way??

Thank you in advance.