code: private VarTensor calcVarBeliefs(Var var) {
          // Compute the product of all messages sent to this variable.
          VarTensor prod = new VarTensor(s, new VarSet(var), s.one());
          calcProductAtVar(var.getId(), prod, -1, -1);
          return prod;
      }
docs: Gets the unnormalized variable beleifs.