Extract interface from implementation in case of Environment and ModuleRegistry

app/src/main/kotlin/io/smnp/environment/DefaultEnvironment.kt

@@ -0,0 +1,20 @@
+package io.smnp.environment
+
+import io.smnp.ext.DefaultModuleRegistry
+import io.smnp.type.module.Module
+
+class DefaultEnvironment : Environment {
+    private val rootModule = Module("<root>")
+    private val loadedModules = mutableListOf<String>()
+
+    override fun loadModule(path: String) {
+        DefaultModuleRegistry.requestModulesForPath(path).forEach {
+            rootModule.addSubmodule(it)
+            loadedModules.add(path)
+        }
+    }
+
+    override fun printModules(printContent: Boolean) {
+        rootModule.pretty(printContent)
+    }
+}

app/src/main/kotlin/io/smnp/ext/DefaultModuleRegistry.kt

@@ -0,0 +1,21 @@
+package io.smnp.ext
+
+import io.smnp.type.module.Module
+import org.pf4j.DefaultPluginManager
+
+object DefaultModuleRegistry : ModuleRegistry {
+    private val modules = mutableListOf<Pair<String, Module>>()
+    init {
+        val pluginManager = DefaultPluginManager()
+        pluginManager.loadPlugins()
+        pluginManager.startPlugins()
+
+        pluginManager.getExtensions(ModuleDefinition::class.java).forEach {
+            modules.add(Pair(it.modulePath(), Module.create(it.modulePath(), it.functions(), it.methods())))
+        }
+    }
+
+    override fun requestModulesForPath(path: String): List<Module> {
+        return modules.filter { it.first == path }.map { it.second }
+    }
+}