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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 deploy_signature(source, dest, user=None, group=None):
 """Deploy a signature fole"""

    move(source, dest)
    os.chmod(dest, 0644)
    if user and group:
        try:
            uid = pwd.getpwnam(user).pw_uid
            gid = grp.getgrnam(group).gr_gid
            os.chown(dest, uid, gid)
        except (KeyError, OSError):
            pass