code: def send_header(self, keyword, value):
          
          if self.request_version != 'HTTP/0.9':
              if not hasattr(self, '_headers_buffer'):
                  self._headers_buffer = []
              self._headers_buffer.append(
                  ("%s: %s\r\n" % (keyword, value)).encode('latin-1', 'strict'))
  
          if keyword.lower() == 'connection':
              if value.lower() == 'close':
                  self.close_connection = 1
              elif value.lower() == 'keep-alive':
                  self.close_connection = 0
docs: Send a MIME header to the headers buffer.