code: public static Expression asBoxedList(List<SoyExpression> items) {
      List<Expression> childExprs = new ArrayList<>(items.size());
      for (SoyExpression child : items) {
        childExprs.add(child.box());
      }
      return BytecodeUtils.asList(childExprs);
    }
docs: Returns an Expression that evaluates to a list containing all the items as boxed soy values.