code: def fix_w391(self, _):
          
          blank_count = 0
          for line in reversed(self.source):
              line = line.rstrip()
              if line:
                  break
              else:
                  blank_count += 1
  
          original_length = len(self.source)
          self.source = self.source[:original_length - blank_count]
          return range(1, 1 + original_length)
docs: Remove trailing blank lines.