message: Add seed for random event downsampling
diff: @@ -187,9 +187,10 @@ public:
  void ApplyPhysicsSelectionOnline(bool apply=true) { fApplyPhysicsSelOnline = apply; }
  - void EnableEventDownsampling(float fractokeep) {
  + void EnableEventDownsampling(float fractokeep, unsigned long seed) {
  fEnableEventDownsampling = true;
  fFracToKeepEventDownsampling = fractokeep;
  + fSeedEventDownsampling = seed;
  }
  // Particles (tracks or MC particles)
  