Fixed #4463

core/src/mindustry/world/blocks/power/PowerGraph.java

@@ -292,6 +292,16 @@ public class PowerGraph{
         }
     }
 
+    /** Used for unit tests only. */
+    public void removeList(Building build){
+        all.remove(build);
+        producers.remove(build);
+        consumers.remove(build);
+        batteries.remove(build);
+    }
+
+    /** Note that this does not actually remove the building from the graph;
+     * it creates *new* graphs that contain the correct buildings. */
     public void remove(Building tile){
 
         //go through all the connections of this tile

tests/src/test/java/power/PowerTests.java

@@ -130,7 +130,7 @@ public class PowerTests extends PowerTestFixture{
 
             assertEquals(1.0f, consumerTile.build.power.status, Mathf.FLOAT_ROUNDING_ERROR);
 
-            powerGraph.remove(producerTile.build);
+            powerGraph.removeList(producerTile.build);
             powerGraph.add(consumerTile.build);
             powerGraph.update();