[struts2] Taglib and freemarker -> insert bodyContent

[OTB]

Hi, I succeeded to create a taglib using a ftl template.
I can esaly access from the template to my parameters with
${parameters.XXX},
but how to insert, inside my template, the body content of my tag ?

I would like to generate this :

START
some large generated stufff
my <b>custom</b>content
some large generated stuff2
END


with that code :

START
<tag:test>
my <b>custom</b> content
</tag:test>
END


Thanks.