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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 update_time_range(form_data):
 """Move since and until to time_range."""

    if 'since' in form_data or 'until' in form_data:
        form_data['time_range'] = '{} : {}'.format(
            form_data.pop('since', '') or '',
            form_data.pop('until', '') or '',
        )