old_contents: import os
  import sys
  sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
  
  import requests
  
  
  def fetch_html_document(url):
      """Fetch html from url and return html
  
      :param str url: an address to a resource on the Internet
      :return no except hit: status code and html of page (if exists)
      :rtype: tuple
      :return except hit: error
      :rtype: str
      """
      try:
          response = requests.get(url)
          if response.status_code == requests.codes.ok:
              return response.status_code, response.text # html
          else:
              return response.status_code, response.text
      except Exception as err:
          return err
  
new_contents: import os
  import sys
  sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
  
  import requests
  
  
  def fetch_html_document(url, user_agent='python_requests.cli-ws'):
      """Fetch html from url and return html
  
      :param str url: an address to a resource on the Internet
      :opt param str user_agent: user agent that the request will be made with
      :return no except hit: status code and html of page (if exists)
      :rtype: tuple
      :return except hit: error
      :rtype: str
      """
      try:
          response = requests.get(url, headers={'User-Agent': user_agent})
          if response.status_code == requests.codes.ok:
              return response.status_code, response.text # html
          else:
              return response.status_code, response.text
      except Exception as err:
          return err
  
subject: Add user-agent field to html_fetcher