'Validates the client supplied redirection URI.
:param client_key: The client/consumer key.
:param redirect_uri: The URI the client which to redirect back to after
authorization is successful.
:param request: An oauthlib.common.Request object.
:returns: True or False
It is highly recommended that OAuth providers require their clients
to register all redirection URIs prior to using them in requests and
register them as absolute URIs. See `CWE-601`_ for more information
about open redirection attacks.
By requiring registration of all redirection URIs it should be
straightforward for the provider to verify whether the supplied
redirect_uri is valid or not.
Alternatively per `Section 2.1`_ of the spec:
"If the client is unable to receive callbacks or a callback URI has
been established via other means, the parameter value MUST be set to
"oob" (case sensitive), to indicate an out-of-band configuration."
.. _`CWE-601`: http://cwe.mitre.org/top25/index.html#CWE-601
.. _`Section 2.1`: https://tools.ietf.org/html/rfc5849#section-2.1
This method is used by
* RequestTokenEndpoint'

def validate_redirect_uri(self, client_key, redirect_uri, request):

    raise NotImplementedError(u'Subclasses    must    implement    this    function.')
