--- old/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/gc/z/ZCollectedHeap.java	2019-02-11 14:47:36.022999603 +0100
+++ new/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/gc/z/ZCollectedHeap.java	2019-02-11 14:47:35.638999616 +0100
@@ -34,6 +34,7 @@
 import sun.jvm.hotspot.runtime.VMObjectFactory;
 import sun.jvm.hotspot.types.Type;
 import sun.jvm.hotspot.types.TypeDataBase;
+import sun.jvm.hotspot.utilities.BitMapInterface;
 
 // Mirror class for ZCollectedHeap.
 
@@ -117,4 +118,10 @@
             return handle.toString();
         }
     }
+
+    @Override
+    public BitMapInterface createBitMap(long size) {
+        // Ignores the size
+        return new ZExternalBitMap(this);
+    }
 }