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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 _import_sub_module(module, name):
 """import_sub_module will mimic the function of importlib.import_module"""

    module = __import__(module.__name__ + "." + name)
    for level in name.split("."):
        module = getattr(module, level)
    return module