'Ensure the request is valid.
The client constructs the request by including the following parameters
using the "application/x-www-form-urlencoded" format in the HTTP
request entity-body:
token (REQUIRED).  The token that the client wants to get revoked.
token_type_hint (OPTIONAL).  A hint about the type of the token
submitted for revocation.  Clients MAY pass this parameter in order to
help the authorization server to optimize the token lookup.  If the
server is unable to locate the token using the given hint, it MUST
extend its search accross all of its supported token types.  An
authorization server MAY ignore this parameter, particularly if it is
able to detect the token type automatically.  This specification
defines two such values:
*  access_token: An Access Token as defined in [RFC6749],
`section 1.4`_
*  refresh_token: A Refresh Token as defined in [RFC6749],
`section 1.5`_
Specific implementations, profiles, and extensions of this
specification MAY define other values for this parameter using
the registry defined in `Section 4.1.2`_.
The client also includes its authentication credentials as described in
`Section 2.3`_. of [`RFC6749`_].
.. _`section 1.4`: http://tools.ietf.org/html/rfc6749#section-1.4
.. _`section 1.5`: http://tools.ietf.org/html/rfc6749#section-1.5
.. _`section 2.3`: http://tools.ietf.org/html/rfc6749#section-2.3
.. _`Section 4.1.2`: http://tools.ietf.org/html/draft-ietf-oauth-revocation-11#section-4.1.2
.. _`RFC6749`: http://tools.ietf.org/html/rfc6749'

def validate_revocation_request(self, request):

    if (not request.token):
        raise InvalidRequestError(request=request, description=u'Missing    token    parameter.')
    if self.request_validator.client_authentication_required(request):
        if (not self.request_validator.authenticate_client(request)):
            log.debug(u'Client    authentication    failed,    %r.', request)
            raise InvalidClientError(request=request)
    elif (not self.request_validator.authenticate_client_id(request.client_id, request)):
        log.debug(u'Client    authentication    failed,    %r.', request)
        raise InvalidClientError(request=request)
    if (request.token_type_hint and (request.token_type_hint in self.valid_token_types) and (request.token_type_hint not in self.supported_token_types)):
        raise UnsupportedTokenTypeError(request=request)
