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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 format(self, data: Iterable[_FormatArg]) -> bytes: """String interpolation into the format string. Args: data: The data interpolated into the format string. Examples: :: BytesFormat(b'Hello, %b!') % b'World' BytesFormat(b'%b, %b!') % (b'Hello', b'World') """

        fix_arg = self._fix_format_arg
        return self.how % tuple(fix_arg(item) for item in data)