def _get_signature_method(self, oauth_request):
        try:
            signature_method = oauth_request.get_parameter('oauth_signature_method')
        except:
            signature_method = SIGNATURE_METHOD
        try:
            # get the signature method object
            signature_method = self.signature_methods[signature_method]
        except:
            signature_method_names = ', '.join(self.signature_methods.keys())
            raise OAuthError((signature_method, signature_method_names) % 'Signature method %s not supported try one of the following: %s')

        return signature_method
dataset/ETHPy150Open benadida/helios-server/helios_auth/security/oauth.py/OAuthServer._get_signature_method/swapped operands of `%`