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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_resource_attribute(self, attr):
 """Gets the resource attribute if available :param attr: Name of the attribute :return: Value of the attribute, if set in the resource. None otherwise """

        if attr not in self.resource_attributes:
            raise KeyError("%s is not in resource attributes" % attr)

        return self.resource_attributes[attr]