cms.ESProducer("PropagatorWithMaterialESProducer",    ComponentName = cms.string('PropagatorWithMaterialOpposite'),    Mass = cms.double(0.105),    MaxDPhi = cms.double(1.6),    PropagationDirection = cms.string('oppositeToMomentum'),    SimpleMagneticField = cms.string(''),    ptMin = cms.double(-1.0),    useRungeKutta = cms.bool(False))