Add Engine.getSubsystem

base/src/main/kotlin/de/staropensource/engine/base/Engine.kt

@@ -27,6 +27,7 @@ import de.staropensource.engine.base.utility.FileAccess
 import de.staropensource.engine.base.utility.dnihbd.BuildInformation
 import java.nio.charset.Charset
 import java.nio.charset.StandardCharsets
+import kotlin.reflect.KClass
 
 /**
  * Primary class of the engine.
@@ -102,6 +103,18 @@ class Engine private constructor() {
          */
         fun getSubsystems(): Array<Subsystem> = subsystems.toTypedArray()
 
+        /**
+         * Returns the loaded instance
+         * of the specified [Subsystem].
+         *
+         * @since v1-alpha10
+         */
+        fun getSubsystem(subsystemClass: KClass<out Subsystem>): Subsystem? = getSubsystems().find { subsystem -> try {
+            subsystem::class.qualifiedName!! == subsystemClass.qualifiedName!!
+        } catch (_: NullPointerException) {
+            false
+        } }
+
         /**
          * Registers the specified subsystem.
          *