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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 organisation_logo(self, logo):
 """Set image that will be used as organisation logo in reports. :param logo: Path to the organisation logo image. :type logo: str """

        if isinstance(logo, str) and os.path.exists(logo):
            self._organisation_logo = logo
        else:
            self._organisation_logo = supporters_logo_path()