15// values are taken from https://github.com/cms-sw/cmssw/blob/master/MagneticField/GeomBuilder/plugins/VolumeBasedMagneticFieldESProducerFromDB.cc#L74-L75
37// logic is taken from https://github.com/cms-sw/cmssw/blob/master/MagneticField/GeomBuilder/plugins/VolumeBasedMagneticFieldESProducerFromDB.cc#L156