Create GameModeExtensions.kt

src/main/kotlin/net/axay/kspigot/extensions/bukkit/GameModeExtensions.kt

@@ -0,0 +1,11 @@
+package net.axay.kspigot.extensions.bukkit
+
+import org.bukkit.GameMode
+
+val GameMode.isDamageable: Boolean
+    get() = when (this) {
+        GameMode.SURVIVAL -> true
+        GameMode.ADVENTURE -> true
+        GameMode.SPECTATOR -> false
+        GameMode.CREATIVE -> false
+    }