code: def run(self, lines):
          
          ret = []
          for line in lines:
              while True:
                  match = re.search(r'\[(.*?)\]\((.*?\.md)\)', line)
                  if match != None:
                      title = match.group(1)
                      line = re.sub(r'\[.*?\]\(.*?\.md\)', title, line, count=1)
                  else:
                      break
              ret.append(line)
  
          return ret
docs: Filter method