it is done

core/src/mindustry/world/producers/Produce.java

@@ -0,0 +1,4 @@
+package mindustry.world.producers;
+
+public class Produce{
+}

core/src/mindustry/world/producers/ProduceItem.java

@@ -0,0 +1,4 @@
+package mindustry.world.producers;
+
+public class ProduceItem{
+}