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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 _pwm_to_str(self, precision=4):
 """Return string representation of pwm. Parameters precision : int, optional, default 4 Floating-point precision. Returns ------- pwm_string : str """

        if not self.pwm:
            return ""
        
        fmt = "{{:.{:d}f}}".format(precision)
        return "\n".join(
                ["\t".join([fmt.format(p) for p in row])
                for row in self.pwm]
                )