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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 precondition(precond):
 """ Runs the callable responsible for making some assertions about the data structure expected for the transformation. If the precondition is not achieved, a UnmetPrecondition exception must be raised, and then the transformation pipe is bypassed. """

    def decorator(f):
        """`f` can be a reference to a method or function. In
        both cases the `data` is expected to be passed as the
        first positional argument (obviously respecting the
        `self` argument when it is a method).
        """
        def decorated(*args):
            if len(args) > 2:
                raise TypeError('%s takes only 1 argument (or 2 for instance methods)' % f.__name__)

            try:
                instance, data = args
                if not isinstance(instance, Pipe):
                    raise TypeError('%s is not a valid pipe instance' % instance)

            except ValueError:  # tuple unpacking error
                data = args[0]

            try:
                precond(data)
            except UnmetPrecondition:
                # bypass the pipe
                return data
            else:
                return f(*args)
        return decorated
    return decorator