def set_dst! a, d
            @action = a
            if d.is_a? Edoors::Iota
                @dst = d
            else
                @dst = nil
                _split_path! d
            end
        end
def set_dst! a, d
            @action = a
            if d.is_a? Edoors::Iota
                @dst = d
            else
                @dst = nil
                _split_path! d
            end
        end
sets the current destination

 @param [String] a the action
 @param [String Iota] d the destination