'Create an object that represents a SAML Issuer.
<ns0:Issuer
xmlns:ns0="urn:oasis:names:tc:SAML:2.0:assertion"
Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity">
https://acme.com/FIM/sps/openstack/saml20</ns0:Issuer>
:returns: XML <Issuer> object'

def _create_issuer(self, issuer_url):

    issuer = saml.Issuer()
    issuer.format = saml.NAMEID_FORMAT_ENTITY
    issuer.set_text(issuer_url)
    return issuer
