There is the PHP method eZ\Publish\API\Repository\ContentTypeService::isContentTypeUsed

During v2 development it occurred to us that it would be nice to have syntax sugar like isContentTypeGroupUsed which would return true if any of the ContentTypes assigned to that group returns true for isContentTypeUsed, so we could avoid calling loadContentTypes

Specification: It should be implemented not as a facade but as direct call to persistence layer to make it more efficient.

// cc lukasz.serwatka@ez.no, bertrand.dunogier@ez.no, mikolaj.adamczyk@ez.no