MDG : List UIBB - need to add rows in method get_data in feeder class with ct_data

My requirement is to display number of rows of data in List display via clicking on button.

when creating custom event in get_definition and passing that event to button not able to display record in that

I am not able to add rows in CT_DATA table of method GET_DATA, feeder class is custom. Parent class is CL_MDG_BS_GUIBB_LIST.

What needs to be done for that? every time event refreshes and ct_data is blank, even if gets added the row goes greyed out and nothing is in display.

Need to add in flush method? what could be possible solution?

Thanks in Advance