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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 _get_template(self, template_name):
 """ Retrieve the cached version of the template """

        if template_name not in self.chached_templates:
            self.chached_templates[template_name] = self.env.get_template(template_name)
        return self.chached_templates[template_name]