Returns whether sibling is one of renderer’s focus siblings (see gtk.cell_area.CellArea.addFocusSibling).
the gtk.cell_renderer.CellRenderer expected to have focus
the gtk.cell_renderer.CellRenderer 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).