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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 format_index(data):
 """Create UTC localized DatetimeIndex for the dataframe. Parameters data: Dataframe Must contain columns 'year', 'jday', 'hour' and 'minute'. Return ------ data: Dataframe Dataframe with a DatetimeIndex localized to UTC. """

    year = data.year.apply(str)
    jday = data.jday.apply(lambda x: '{:03d}'.format(x))
    hours = data.hour.apply(lambda x: '{:02d}'.format(x))
    minutes = data.minute.apply(lambda x: '{:02d}'.format(x))
    index = pd.to_datetime(year + jday + hours + minutes, format="%Y%j%H%M")
    data.index = index
    data = data.tz_localize('UTC')
    return data