the module name that the template only component represents, this will be used for debugging purposes

This utility function is used to declare a given component has no backing class. When the rendering engine detects this it is able to perform a number of optimizations. Templates that are associated with templateOnly() will be rendered as is without adding a wrapping <div> (or any of the other element customization behaviors of @ember/component). Specifically, this means that the template will be rendered as "outer HTML".

In general, this method will be used by build time tooling and would not be directly written in an application. However, at times it may be useful to use directly to leverage the "outer HTML" semantics mentioned above. For example, if an addon would like to use these semantics for its templates but cannot be certain it will only be consumed by applications that have enabled the template-only-glimmer-components optional feature.