

def is_byte_range_valid(start, stop, length):
    'Checks if a given byte content range is valid for the given length.\n\n    .. versionadded:: 0.7\n    '
    if ((start is None) != (stop is None)):
        return False
    elif (start is None):
        return ((length is None) or (length >= 0))
    elif (length is None):
        return (0 <= start < stop)
    elif (start >= stop):
        return False
    return (0 <= start < length)

dataset/ETHPy150Open Eforcers/gae-flask-todo/lib/werkzeug/http.py is_byte_range_valid/original