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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 update(self, properties=None, description=None):
 """Update this application configuration. To create or update a property provide its key-value pair in `properties`. To delete a property provide its key with the value ``None`` in properties. Args: properties (dict):
 Property values to be updated. If ``None`` the properties are unchanged. description (str):
 Description for the configuration. If ``None`` the description is unchanged. Returns: ApplicationConfiguration: self """

        cv = ApplicationConfiguration._props(properties=properties, description=description)
        res = self.rest_client.session.patch(self.rest_self,
            headers = {'Accept' : 'application/json',
                       'Content-Type' : 'application/json'},
            json=cv)
        _handle_http_errors(res)
        self.json_rep = res.json()
        return self