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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 desc(t=None, reg=True):
 """ Describe Class Dependency :param reg: should we register this class as well :param t: custom type as well :return: """


    def decorated_fn(cls):
        if not inspect.isclass(cls):
            return NotImplemented('For now we can only describe classes')
        name = t or camel_case_to_underscore(cls.__name__)[0]
        if reg:
            di.injector.register(name, cls)
        else:
            di.injector.describe(name, cls)
        return cls

    return decorated_fn