EngineFeature

object EngineFeature : 
    ApplicationFeature<EnginePipeline, Configuration, ShutDownUrl>

A feature to install into engine pipeline

key	`val key: AttributeKey<ShutDownUrl>` Unique key that identifies a feature

fun install(
    pipeline: EnginePipeline, 
    configure: Configuration.() -> Unit
): ShutDownUrl

Feature installation script