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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 _process_json(data):
 """ return a list of GradLeave objects. """

    requests = []
    for item in data:
        leave = GradLeave()
        leave.reason = item.get('leaveReason')
        leave.submit_date = datetime_from_string(item.get('submitDate'))
        if item.get('status') is not None and len(item.get('status')) > 0:
            leave.status = item.get('status').lower()

        for quarter in item.get('quarters'):
            term = GradTerm()
            term.quarter = quarter.get('quarter').lower()
            term.year = quarter.get('year')
            leave.terms.append(term)
        requests.append(leave)
    return requests