How can you use assingInclude for include blocks that are inside an included block using TemplatePower?

I'm new to TemplatePower. How can I use assingInclude for include blocks that are inside an included block using TemplatePower?

So for example, I use:

<!-- INCLUDE BL开发者_运维知识库OCK block_1 -->

Then in PHP I use:

$tpl->assignInclude('block_1', 'block_1.tpl');

Then inside block_1.tpl, I want to use the same principle. For example:

<!-- INCLUDE BLOCK block_2 -->

And again in the PHP I use:

$tpl->assignInclude('block_2', 'block_2.tpl');

Why isn't it working?

I think this is because you are using

<!-- INCLUDE BLOCK block_2 -->

But you have to use

<!-- INCLUDE BLOCK : block_2 -->

You have to use : in order to make it work