can i create new row manually by using cl_gui_alv_tree_simple?

Hi Experts,

    Now i am using CL_GUI_ALV_TREE_SIMPLE standard class. In that class i could not find ADD_NODE method, Instead of that i can find TREE_ADD_NODE method. How can i use that method?

  I want to create a new row for total & subtotal values display. if i click the summation button the total & subtotal values should displayed in the new line(last line).

Screen shot as below for reference.

Regards,

Kalpana.