def sumSeries(requestContext, *seriesLists):
    """
    Short form: sum()

    This will add metrics together and return the sum at each datapoint. (See
    integral for a sum over time)

    Example::

        &target=sum(company.server.application*.requestsHandled)

    This would show the sum of all requests handled per minute (provided
    requestsHandled are collected once a minute).     If metrics with different
    retention rates are combined, the coarsest metric is graphed, and the sum
    of the other metrics is averaged for the metrics with finer retention
    rates.

    """
    if not seriesLists or not any(seriesLists):
        return []
    seriesList, start, end, step = normalize(seriesLists)
    name = "sumSeries(%s)" % formatPathExpressions(seriesList)
    values = (safeSum(row) for row in zip_longest(*seriesList))
    series = TimeSeries(name, start, end, step, values)
    series.pathExpression = name
    return [series]

    Short form: sum()

    This will add metrics together and return the sum at each datapoint. (See
    integral for a sum over time)

    Example::

        &target=sum(company.server.application*.requestsHandled)

    This would show the sum of all requests handled per minute (provided
    requestsHandled are collected once a minute).     If metrics with different
    retention rates are combined, the coarsest metric is graphed, and the sum
    of the other metrics is averaged for the metrics with finer retention
    rates.

    
graphite_api/functions.py