# File lib/maruku/input/parse_span_better.rb, line 693
                def push_element(e)
                        raise "Only MDElement and String, please. You pushed #{e.class}: #{e.inspect} " if
                         not (e.kind_of?(String) or e.kind_of?(MDElement))
                
                        push_string_if_present
                        @elements << e
                        nil
                end