Gtk.TreeViewColumn.prototype.cell_get_position

function cell_get_position(cell_renderer:Gtk.CellRenderer):Boolean {
    // Gjs wrapper for gtk_tree_view_column_cell_get_position()
}

Obtains the horizontal position and size of a cell in a column. If the cell is not found in the column, @start_pos and width are not changed and false is returned.