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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 validate(self):
 """ Perform validation check on properties. """

        if not self.api_token or not self.api_token_secret:
            raise ImproperlyConfigured("'api_token' and 'api_token_secret' are required for authentication.")

        if self.response_type not in ["json", "pson", "xml", "debug", None]:
            raise ImproperlyConfigured("'%s' is an invalid response_type" % self.response_type)