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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 get_ed25519ll():
 """Lazy import-and-test of ed25519 module"""

    global ed25519ll

    if not ed25519ll:
        try:
            import ed25519ll  # fast (thousands / s)
        except (ImportError, OSError):  # pragma nocover
            from . import ed25519py as ed25519ll  # pure Python (hundreds / s)
        test()

    return ed25519ll