code: def as_lines(self):
          
  
          out_lines = []
          for t,v in self.lines:
  
              # Make the output prettier
              if t == 'Section':
                  out_lines.append('')
  
              out_lines.append('{}: {}'.format(t,v if v is not None else '') )
  
          return '\n'.join(out_lines)
docs: Return a Lines representation as a string