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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 op_count(cls, crawler, stage=None):
 """Total operations performed for this crawler"""

        if stage:
            total_ops = conn.get(make_key(crawler, stage))
        else:
            total_ops = conn.get(make_key(crawler, "total_ops"))
        return unpack_int(total_ops)