'Construct a HEAD request.'

def head(self, path, data={}, **extra):

    parsed = urlparse(path)
    query_string = (urlencode(data, doseq=True) or force_str(parsed[4]))
    if six.PY3:
        query_string = query_string.encode(u'utf-8').decode(u'iso-8859-1')
    r = {u'PATH_INFO': self._get_path(parsed), u'QUERY_STRING': query_string, u'REQUEST_METHOD': str(u'HEAD')}
    r.update(extra)
    return self.request(**r)
