if (globalTensor.getIsMutable()) {
        freezeable[val] = false;
        continue;
      }

      freezeable[val] = true;

      // Verify users are supported kind.
      for (Operation *user : val.getUsers()) {
        if (!(isa<TF::ReadVariableOp>(user) || isa<CallOpInterface>(user))) {
          freezeable[val] = false;
          // Error out early if possible.