docs: @Nullable
    public <A extends AbstractValue<A>, S extends Store<S>, T extends TransferFunction<A, S>>
        A expressionDataflow(TreePath exprPath, Context context, T transfer) {
      AnalysisResult<A, S> analysisResult = resultForExpr(exprPath, context, transfer);
      return analysisResult == null ? null : analysisResult.getValue(exprPath.getLeaf());
    }