def default_middlewares(web3):
        """
        List the default middlewares for the request manager.
        Leaving ens unspecified will prevent the middleware from resolving names.
        """
        return [
            (request_parameter_normalizer, 'request_param_normalizer'),
            (gas_price_strategy_middleware, 'gas_price_strategy'),
            (name_to_address_middleware(web3), 'name_to_address'),
            (attrdict_middleware, 'attrdict'),
            (pythonic_middleware, 'pythonic'),
            (normalize_errors_middleware, 'normalize_errors'),
            (validation_middleware, 'validation'),
            (abi_middleware, 'abi'),
        ]
List the default middlewares for the request manager.
        Leaving ens unspecified will prevent the middleware from resolving names.