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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 checkout(self, repo_dir, shared_dir, **kwargs):
 """This function checks out code from a Git SCM server."""

        del kwargs
        args = []
        for checkout_fn in _CHECKOUT_ARG_BUILDERS:
            args.extend(checkout_fn(shared_dir, repo_dir, self._args))
        return args