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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 _check_realign(data):
 """Check for realignment, which is not supported in GATK4 """

    if "gatk4" not in data["algorithm"].get("tools_off", []) and not "gatk4" == data["algorithm"].get("tools_off"):
        if data["algorithm"].get("realign"):
            raise ValueError("In sample %s, realign specified but it is not supported for GATK4. "
                             "Realignment is generally not necessary for most variant callers." %
                             (dd.get_sample_name(data)))