.. _`Section 3.2.1`: http://tools.ietf.org/html/rfc6749#section-3.2.1
"""
for param in ('grant_type', 'username', 'password'):
.. _`Section 3.2.1`: http://tools.ietf.org/html/rfc6749#section-3.2.1
"""
for param in ('grant_type', 'username', 'password'):
raise errors.InvalidRequestError(
'Request is missing %s parameter.' % param, request=request)
raise errors.InvalidRequestError(
'Request is missing %s parameter.' % param, request=request)