How to nest a quilt within another quilt

I would like to add a quilt within another quilt, I have read that they are nestable, but not sure how to achieve this.

for example:

We have this quilt for Forum Topic Page

<quilt layout="one-column" nestable="false" disableTopCssClass="false">
  <add to="common-footer">
    <component id="community-footer"/>
  </add>
  <add to="main-content">
    <component id="community.widget.page-options"/>
    <component id="topic-message"/>
    <component id="thread-pager"/>
    <component id="solution-count-conditional"/>
    <component id="solution-list"/>
    <component id="reply-count-conditional"/>
    <component id="reply-list"/>
    <component id="message-pager"/>
  </add>
  <add to="common-header">
    <component id="community-header"/>
    <component id="common.widget.breadcrumb"/>
  </add>
  <add to="icons" for="Footer">
    <component id="common.widget.scroll-to"/>
  </add>
</quilt>

I would like to include another quilt entitled Forum Topic Header

<quilt layout="topic-header" nestable="true" disableTopCssClass="false">
  <add to="topic-header-right">
    <component id="solution-link"/>
  </add>
  <add to="topic-header-left">
    <component id="common.widget.page-title"/>
    <component id="solved-indicator"/>
  </add>
</quilt>

How do I include Forum Topic Header in Forum Topic Page.

Thank you