Returns whether sibling is one of renderer’s focus siblings (see gtk.cell_area.CellArea.addFocusSibling).
the #GtkCellRenderer expected to have focus
the #GtkCellRenderer to check against renderer’s sibling list
true if sibling is a focus sibling of renderer
Returns whether sibling is one of renderer’s focus siblings (see gtk.cell_area.CellArea.addFocusSibling).