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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_source( self, environment: Environment, template: str, ) -> Tuple[str, Optional[str], Callable]: """Returns the template source from the environment. This considers the loaders on the :attr:`app` and blueprints. """

        for loader in self._loaders():
            try:
                return loader.get_source(environment, template)
            except TemplateNotFound:
                continue
        raise TemplateNotFound(template)