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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 tracked_array(array, dtype=None):
 """ Properly subclass a numpy ndarray to track changes. Avoids some pitfalls of subclassing by forcing contiguous arrays, and does a view into a TrackedArray. Parameters array : array- like object To be turned into a TrackedArray dtype : np.dtype Which dtype to use for the array Returns tracked : TrackedArray Contains input array data """

    # if someone passed us None, just create an empty array
    if array is None:
        array = []
    # make sure it is contiguous then view it as our subclass
    tracked = np.ascontiguousarray(
        array, dtype=dtype).view(TrackedArray)
    # should always be contiguous here
    assert tracked.flags['C_CONTIGUOUS']

    return tracked