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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def extent_string_to_array(extent_text):
 """Convert an extent string to an array. .. versionadded: 2.2.0 :param extent_text: String representing an extent e.g. 109.829170982, -8.13333290561, 111.005344795, -7.49226294379 :type extent_text: str :returns: A list of floats, or None :rtype: list, None """

    coordinates = extent_text.replace(' ', '').split(',')
    count = len(coordinates)
    if count != 4:
        message = (
            'Extent need exactly 4 value but got %s instead' % count)
        LOGGER.error(message)
        return None

    # parse the value to float type
    try:
        coordinates = [float(i) for i in coordinates]
    except ValueError as e:
        message = str(e)
        LOGGER.error(message)
        return None
    return coordinates