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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_client(self, request=None):
 """Return the client from the OAuth parameters."""


        if not isinstance(request, oauth.Request):
            request = self.get_oauth_request()
        client_key = request.get_parameter('oauth_consumer_key')
        if not client_key:
            raise Exception('Missing "oauth_consumer_key" parameter in ' \
                'OAuth "Authorization" header')

        client = models.Client.get_by_key_name(client_key)
        if not client:
            raise Exception('Client "%s" not found.' % client_key)

        return client