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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 word_wrap(self):
 """ Read-write setting determining whether lines of text in this shape are wrapped to fit within the shape's width. Valid values are True, False, or None. True and False turn word wrap on and off, respectively. Assigning None to word wrap causes any word wrap setting to be removed from the text frame, causing it to inherit this setting from its style hierarchy. """

        return {
            ST_TextWrappingType.SQUARE: True,
            ST_TextWrappingType.NONE:   False,
            None:                       None
        }[self._txBody.bodyPr.wrap]