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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 _function_lookup(name, module):
 """Searches the function between the registered ones. If not found, it imports the module forcing its registration. """

    try:
        return _registered_functions[name]
    except KeyError:  # force function registering
        __import__(module)
        mod = sys.modules[module]
        getattr(mod, name)

        return _registered_functions[name]