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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 none(n, coef):
 """ Build a matrix of zeros for features that should go unpenalized Parameters n : int number of splines coef : unused for compatibility with constraints Returns ------- penalty matrix : sparse csc matrix of shape (n,n) """

    return sp.sparse.csc_matrix(np.zeros((n, n)))