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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 f_cash(x, counts, bkg, model):
 """ Wrapper for cash statistics, that defines the model function. Parameters x : float Model amplitude. counts : `~numpy.ndarray` Count map slice, where model is defined. bkg : `~numpy.ndarray` Background map slice, where model is defined. model : `~numpy.ndarray` Source template (multiplied with exposure). """


    return 2.0 * poisson_log_like(counts, bkg + x * model)