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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 zinb_ll(data, P, R, Z):
 """ Returns the zero-inflated negative binomial log-likelihood of the data. """

    lls = nb_ll(data, P, R)
    clusters = P.shape[1]
    for c in range(clusters):
        pass
    return lls