Bulk Extension Registration (Extension Groups)
As an alternative method to register extensions in bulk or groups.
Using the ExtensionGroup API it is possible to define a set of extension grouped under a name to be registered later.
final String groupName = "my-extensions";
ExtensionGroup extensionGroup = asciidoctor.createGroup(groupName)
        .blockMacro(GistBlockMacroProcessor.class)
        .includeProcessor(LsIncludeProcessor.class)
        .postprocessor(ByePostprocessor.class);       (1)
    ...
extensionGroup.register();                            (2)| 1 | Multiple extensions can be added together using the fluent API. | 
| 2 | Complete registration, otherwise extensions won’t be enabled. | 
If you don’t need or want to set a specific name, you can just use asciidoctor.createGroup(), and a randomly generated name will be assigned automatically.
| Calling  This does not apply to  |