startRegistryMap

fun <T : Any, R : T> ConfigEntryBuilder.startRegistryMap(
    fieldNameKey: Component, 
    value: Map<String, T>, 
    factory: () -> T, 
    subclass: KClass<R>? = null, 
    registry: Registry<T>
): RegistryMapBuilder<T, R>

See startSpecField. Builds a String-keyed map of registry entries; factory supplies a value for newly-inserted rows.