code: SoyExpression compile(ExprNode node) {
      Label reattachPoint = new Label();
      final SoyExpression exec = compile(node, reattachPoint);
      return exec.withSource(exec.labelStart(reattachPoint));
    }
docs: Compiles the given expression tree to a sequence of bytecode in the current method visitor.
  
  <p>The generated bytecode expects that the evaluation stack is empty when this method is called
  and it will generate code such that the stack contains a single SoyValue when it returns. The
  SoyValue object will have a runtime type equal to {@code node.getType().javaType()}.