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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 column_widths(self, size, focus=False):
 """ Return a list of column widths. 0 values in the list mean hide corresponding column completely """

        maxcol = size[0]
        self._cache_maxcol = maxcol
        widths = [width for i, (w, (t, width, b)) in enumerate(self.contents)]
        self._cache_column_widths = widths

        return widths