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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_sign_key(exported_session_key, magic_constant):
 """ 3.4.5.2 SIGNKEY @param exported_session_key: A 128-bit session key used to derive signing and sealing keys @param magic_constant: A constant value set in the MS-NLMP documentation (constants.SignSealConstants) @return sign_key: Key used to sign messages """


    sign_key = hashlib.md5(exported_session_key + magic_constant).digest()

    return sign_key