'Check for duplicate params'

def test_multiple_source_params(self):

    v = RequestValidator()
    e = BaseEndpoint(v)
    self.assertRaises(errors.InvalidRequestError, e._create_request, u'https://a.b/?oauth_signature_method=HMAC-SHA1', u'GET', u'oauth_version=foo', URLENCODED)
    headers = {u'Authorization': u'OAuth    oauth_signature="foo"'}
    headers.update(URLENCODED)
    self.assertRaises(errors.InvalidRequestError, e._create_request, u'https://a.b/?oauth_signature_method=HMAC-SHA1', u'GET', u'oauth_version=foo', headers)
    headers = {u'Authorization': u'OAuth    oauth_signature_method="foo"'}
    headers.update(URLENCODED)
    self.assertRaises(errors.InvalidRequestError, e._create_request, u'https://a.b/', u'GET', u'oauth_signature=foo', headers)
