def _warn_if_string(iterable):
    """Helper for the response objects to check if the iterable returned
    to the WSGI server is not a string.
    """
    if isinstance(iterable, str):
        from warnings import warn
        warn(Warning(
            'response iterable was set to a string.  This appears to work but means that the server will send the data to the client char, by char.  This is almost never intended behavior, use response.data to assign strings to the response object.'
            ), stacklevel=2)
