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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 _convert(self, format):
 """Return a new Image instance with the given format. Returns self if the format is already the same. """

        if self.format == format:
            return self
        else:
            image = Image(self.pil_image)
            image._format = format
            return image