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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 _pad_string(self, str, colwidth):
 """Center-pads a string to the given column width using spaces."""

        width = self._disp_width(str)
        prefix = (colwidth - 1 - width) // 2
        suffix = colwidth - prefix - width
        return ' ' * prefix + str + ' ' * suffix