Added a simple test to show the original issue

test/Collections.java

@@ -0,0 +1,26 @@
+import java.util.Collection;
+import java.util.Map;
+
+public class Collections {
+  public static void main(String[] args) {
+    testValues();
+  }
+  
+  @SuppressWarnings("rawtypes")
+  private static void testValues() {
+    Map testMap = java.util.Collections.unmodifiableMap(java.util.Collections.emptyMap());
+    Collection values = testMap.values();
+    
+    if (values == null) {
+      throw new NullPointerException();
+    }
+    
+    try {
+      values.clear();
+      
+      throw new IllegalStateException("Object should be immutable, exception should have thrown");
+    } catch (Exception e) {
+      // expected
+    }
+  }
+}