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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 _set_multi_bit_value_format_character(self):
 """ Set format character for multibit values. The format character depends on size of the value and whether values are signed or unsigned. """

        self.MULTI_BIT_VALUE_FORMAT_CHARACTER = \
            self.MULTI_BIT_VALUE_FORMAT_CHARACTER.upper()

        if self.SIGNED_VALUES:
            self.MULTI_BIT_VALUE_FORMAT_CHARACTER = \
                self.MULTI_BIT_VALUE_FORMAT_CHARACTER.lower()