Minor addition to DeserializerCache

src/main/java/com/fasterxml/jackson/databind/deser/DeserializerCache.java

@@ -10,6 +10,7 @@
 import com.fasterxml.jackson.databind.util.ClassUtil;
 import com.fasterxml.jackson.databind.util.Converter;
 import com.fasterxml.jackson.databind.util.LRUMap;
+import com.fasterxml.jackson.databind.util.LookupCache;
 
 /**
  * Class that defines caching layer between callers (like
@@ -34,14 +35,14 @@ public final class DeserializerCache
      * specifically, ones that are expensive to construct.
      * This currently means bean, Enum and container deserializers.
      */
-    final protected LRUMap<JavaType, JsonDeserializer<Object>> _cachedDeserializers;
+    protected final LookupCache<JavaType, JsonDeserializer<Object>> _cachedDeserializers;
 
     /**
      * During deserializer construction process we may need to keep track of partially
      * completed deserializers, to resolve cyclic dependencies. This is the
      * map used for storing deserializers before they are fully complete.
      */
-    final protected HashMap<JavaType, JsonDeserializer<Object>> _incompleteDeserializers
+    protected final HashMap<JavaType, JsonDeserializer<Object>> _incompleteDeserializers
         = new HashMap<JavaType, JsonDeserializer<Object>>(8);
 
     /*
@@ -55,8 +56,14 @@ public DeserializerCache() {
     }
 
     public DeserializerCache(int maxSize) {
-        int initial = Math.min(64, maxSize>>2);
-        _cachedDeserializers = new LRUMap<>(initial, maxSize);
+        this(new LRUMap<>(Math.min(64, maxSize>>2), maxSize));
+    }
+
+    /**
+     * @since 2.16
+     */
+    public DeserializerCache(LookupCache<JavaType, JsonDeserializer<Object>> cache) {
+        _cachedDeserializers = cache;
     }
 
     /*