'Create an object that represents a SAML Response.
<ns0:Response
Destination="http://beta.com/Shibboleth.sso/SAML2/POST"
ID="c5954543230e4e778bc5b92923a0512d"
IssueInstant="2014-07-30T03:19:45Z"
Version="2.0" />
<ns0:Issuer> ... </ns0:Issuer>
<ns0:Assertion> ... </ns0:Assertion>
<ns0:Status> ... </ns0:Status>
</ns0:Response>
:returns: XML <Response> object'

def _create_response(self, issuer, status, assertion, recipient):

    response = samlp.Response()
    response.id = uuid.uuid4().hex
    response.destination = recipient
    response.issue_instant = utils.isotime()
    response.version = '2.0'
    response.issuer = issuer
    response.status = status
    response.assertion = assertion
    return response
