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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 bool_value(self):
 """Infer the truth value for an Instance The truth value of an instance is determined by these conditions: * if it implements __bool__ on Python 3 or __nonzero__ on Python 2, then its bool value will be determined by calling this special method and checking its result. * when this method is not defined, __len__() is called, if it is defined, and the object is considered true if its result is nonzero. If a class defines neither __len__() nor __bool__(), all its instances are considered true. """

        context = contextmod.InferenceContext()
        context.callcontext = contextmod.CallContext(args=[])
        context.boundnode = self

        try:
            result = _infer_method_result_truth(self, BOOL_SPECIAL_METHOD, context)
        except (exceptions.InferenceError, exceptions.AttributeInferenceError):
            # Fallback to __len__.
            try:
                result = _infer_method_result_truth(self, "__len__", context)
            except (exceptions.AttributeInferenceError, exceptions.InferenceError):
                return True
        return result