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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 _merge_lib_dict(d1, d2):
 """ Merges lib_dict `d2` into lib_dict `d1` """

    for required, requirings in d2.items():
        if required in d1:
            d1[required].update(requirings)
        else:
            d1[required] = requirings
    return None