'If this request is a redirect, follow that redirect.  It
is an error if this is not a redirect response.  Returns
another response object.'

def follow(self, **kw):

    assert ((self.status >= 300) and (self.status < 400)), ('You    can    only    follow    redirect    responses    (not    %s)' % self.full_status)
    location = self.header('location')
    (type, rest) = splittype(location)
    (host, path) = splithost(rest)
    return self.test_app.get(location, **kw)
