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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 install_json(self):
 """Return contents of install.json configuration file, loading from disk if required."""

        if self._install_json is None:
            try:
                install_json_filename = os.path.join(os.getcwd(), 'install.json')
                with open(install_json_filename, 'r') as fh:
                    self._install_json = json.load(fh)
            except IOError:
                self.log.warning(u'Could not retrieve App Data.')
                self._install_json = {}
        return self._install_json