Returns default HTTP header we use for requests.

def _default_http_header(self, empty_session_only: bool = False) -> Dict[str, str]:
        """Returns default HTTP header we use for requests."""
        header = {'Accept-Encoding': 'gzip, deflate',
                  'Accept-Language': 'en-US,en;q=0.8',
                  'Connection': 'keep-alive',
                  'Content-Length': '0',
                  'Host': 'www.instagram.com',
                  'Origin': 'https://www.instagram.com',
                  'Referer': 'https://www.instagram.com/',
                  'User-Agent': self.user_agent,
                  'X-Instagram-AJAX': '1',
                  'X-Requested-With': 'XMLHttpRequest'}
        if empty_session_only:
            del header['Host']
            del header['Origin']
            del header['Referer']
            del header['X-Instagram-AJAX']
            del header['X-Requested-With']
        return header