additional test case

pitest-entry/src/test/java/com/example/staticinitializers/delayedexecution/EnumMethodReferenceNotStored.java

@@ -0,0 +1,20 @@
+package com.example.staticinitializers.delayedexecution;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
+
+public enum EnumMethodReferenceNotStored {
+    A(Arrays.asList(1,2,3));
+
+    private final List<Integer> l;
+    EnumMethodReferenceNotStored(List<Integer> list) {
+        l = list.stream()
+                .filter(this::doNotMutate)
+                .collect(Collectors.toList());
+    }
+
+    private boolean doNotMutate(Integer i) {
+        return i > 2;
+    }
+}

pitest-entry/src/test/java/org/pitest/mutationtest/build/intercept/staticinitializers/StaticInitializerInterceptorTest.java

@@ -8,6 +8,7 @@
 import com.example.staticinitializers.NestedEnumWithLambdaInStaticInitializer;
 import com.example.staticinitializers.SecondLevelPrivateMethods;
 import com.example.staticinitializers.SingletonWithWorkInInitializer;
+import com.example.staticinitializers.delayedexecution.EnumMethodReferenceNotStored;
 import com.example.staticinitializers.delayedexecution.EnumMixedFields;
 import com.example.staticinitializers.delayedexecution.StaticFunctionField;
 import com.example.staticinitializers.delayedexecution.StaticSupplierField;
@@ -228,6 +229,16 @@ public void suppressesMutationsForStringsStoredToEnumFields() {
                 .verify();
     }
 
+    @Test
+    public void filtersMutationsForMethodReferencesUsedInEnumConstructor() {
+        v.forClass(EnumMethodReferenceNotStored.class)
+                .forMethod("doNotMutate")
+                .forAnyCode()
+                .mutantsAreGenerated()
+                .allMutantsAreFiltered()
+                .verify();
+    }
+
     private Predicate<MutationDetails> inMethod(String name, String desc) {
         return m -> m.getMethod().equals(name) && m.getId().getLocation().getMethodDesc().equals(desc);
     }