docs: def get_original_vs_converted_diff( original ,converted ):
      '''  Compares the *original* text to *converted* text, and detects changes/differences in 
          morphological annotations. 
  
          The method constructs line-by-line comparison string, where lines are separated by 
          newline, and '***' at the beginning of the line indicates the difference.
  
          Returns a pair: results of the line-by-line comparison as a string, and boolean value
          indicating whether there were any differences.
      '''
      from estnltk.syntax.syntax_preprocessing import convert_Text_to_mrf
      old_layer_mrf = convert_Text_to_mrf( original )
      new_layer_mrf = convert_Text_to_mrf( converted )
      max_len_1 = max([len(l) for l in old_layer_mrf ])
      max_len_2 = max([len(l) for l in new_layer_mrf ])
      max_len   = max( max_len_1, max_len_2 )
      format_str = '{:<'+str(max_len+1)+'}'
      i = 0
      j = 0
      comp_lines = []
      diff_found = False
      while(i < len(old_layer_mrf) or j < len(new_layer_mrf)):
           l1 = old_layer_mrf[i]
           l2 = new_layer_mrf[j]
           # 1) Output line containing tokens
           if not l1.startswith(' ') and not l2.startswith(' '):
              diff = '*** ' if format_str.format(l1) != format_str.format(l2) else '    '
              comp_lines.append( diff+format_str.format(l1)+format_str.format(l2) )
              if diff == '*** ':
                   diff_found = True
              i += 1
              j += 1
           else:
              # 2) Output analysis line(s)
              while(i < len(old_layer_mrf) or j < len(new_layer_mrf)):
                   l1 = old_layer_mrf[i]
                   l2 = new_layer_mrf[j]
                   if l1.startswith(' ') and l2.startswith(' '):
                      diff = '*** ' if format_str.format(l1) != format_str.format(l2) else '    '
                      comp_lines.append( diff+format_str.format(l1)+format_str.format(l2) )
                      if diff == '*** ':
                         diff_found = True
                      i += 1
                      j += 1
                   elif l1.startswith(' ') and not l2.startswith(' '):
                      diff = '*** '
                      comp_lines.append( diff+format_str.format(l1)+format_str.format(' ') )
                      diff_found = True
                      i += 1
                   elif not l1.startswith(' ') and l2.startswith(' '):
                      diff = '*** '
                      comp_lines.append( diff+format_str.format(' ')+format_str.format(l2) )
                      diff_found = True
                      j += 1
                   else:
                      break
      return '\n'.join( comp_lines ), diff_found