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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 stringify_value(value):
 """Convert any value to string. """

    if value is None:
        return u''
    isoformat = getattr(value, 'isoformat', None)
    if isoformat is not None:
        value = isoformat()
    return type(u'')(value)