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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 randomfill(a):
 """Fill masked areas with random noise This is needed for any fft-based operations """

    a = checkma(a)
    #For data that have already been normalized,
    #This provides a proper normal distribution with mean=0 and std=1
    #a = (a - a.mean()) / a.std()
    #noise = a.mask * (np.random.randn(*a.shape))
    noise = a.mask * np.random.normal(a.mean(), a.std(), a.shape)
    #Add the noise
    b = a.filled(0) + noise
    return b