code: def offset(requestContext, seriesList, factor):
      
      for series in seriesList:
          series.name = "offset(%s,%g)" % (series.name, float(factor))
          series.pathExpression = series.name
          for i, value in enumerate(series):
              if value is not None:
                  series[i] = value + factor
      return seriesList
docs: Takes one metric or a wildcard seriesList followed by a constant, and adds
      the constant to each datapoint.
  
      Example::
  
          &target=offset(Server.instance01.threads.busy,10)