def sign_request(self, signature_method, consumer, token):
        """Set the signature parameter to the result of build_signature."""
        # Set the signature method.
        self.set_parameter('oauth_signature_method',
            signature_method.get_name())
        # Set the signature.
        self.set_parameter('oauth_signature',
            self.build_signature(signature_method, consumer, token))
Set the signature parameter to the result of build_signature.
twitter/oauth.py