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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_plugin_by_model(self, model_class):
 """ Return the corresponding plugin for a given model. You can also use the :attr:`ContentItem.plugin <fluent_contents.models.ContentItem.plugin>` property directly. This is the low-level function that supports that feature. """

        self._import_plugins()                       # could happen during rendering that no plugin scan happened yet.
        assert issubclass(model_class, ContentItem)  # avoid confusion between model instance and class here!

        try:
            name = self._name_for_model[model_class]
        except KeyError:
            raise PluginNotFound("No plugin found for model '{0}'.".format(model_class.__name__))
        return self.plugins[name]