code: private boolean propagateToSharedSketch(final long hash) {
      //noinspection StatementWithEmptyBody
      while (localPropagationInProgress.get()) {
      } //busy wait until previous propagation completed
      localPropagationInProgress.set(true);
      final boolean res = shared.propagate(localPropagationInProgress, null, hash);
      //in this case the parent empty_ and curCount_ were not touched
      thetaLong_ = shared.getVolatileTheta();
      return res;
    }
docs: Propagates a single hash value to the shared sketch
  
  @param hash to be propagated