gtk/tree_view_column.go
func (v *TreeViewColumn) FocusCell(cell *CellRenderer) {
	C.gtk_tree_view_column_focus_cell(v.native(), cell.native())
}
func (v *TreeViewColumn) FocusCell(cell *CellRenderer) {
	C.gtk_tree_view_column_focus_cell(v.native(), cell.native())
}
// FocusCell() is a wrapper around gtk_tree_view_column_focus_cell().