Runtime workflow configuration. In Arcanist, commands you type like "arc diff" or "arc lint" are called "workflows". This class allows you to add new workflows (and extend existing workflows) by subclassing it and then pointing to your subclass in your project configuration.

When specified as the arcanist_configuration class in your project's .arcconfig, your subclass will be instantiated (instead of this class) and be able to handle all the method calls. In particular, you can:

• create, replace, or disable workflows by overriding buildWorkflow() and buildAllWorkflows();
• add additional steps before or after workflows run by overriding willRunWorkflow() or didRunWorkflow() or didAbortWorkflow(); and
• add new flags to existing workflows by overriding getCustomArgumentsForCommand().