code: def send_keys(self, keys, wait=True):
          
          self._process.stdin.write(bytearray(keys, self._encoding))
          self._process.stdin.flush()
          if wait:
              self.wait()
docs: Send a raw key sequence to *Vim*.
  
          .. note:: *Vim* style key sequence notation (like ``<Esc>``)
                    is not recognized.
                    Use escaped characters (like ``'\033'``) instead.
  
          Example:
  
          >>> import headlessvim
          >>> with headlessvim.open() as vim:
          ...     vim.send_keys('ispam\033')
          ...     str(vim.display_lines()[0].strip())
          ...
          'spam'
  
          :param strgin keys: key sequence to send
          :param boolean wait: whether if wait a response