Feature

companion object Feature : 
    HttpClientFeature<Config, HttpPlainText>

key	`val key: AttributeKey<HttpPlainText>` The AttributeKey for this feature.

install	`fun install(feature: HttpPlainText, scope: HttpClient): Unit` Installs the feature class for a HttpClient defined at scope.
prepare	`fun prepare(block: Config.() -> Unit): HttpPlainText` Builds a TFeature by calling the block with a TConfig config instance as receiver.