code: private void onMiss(long key) {
      FrequencyNode freq1 = (freq0.next.count == 1)
          ? freq0.next
          : new FrequencyNode(1, freq0);
      Node node = new Node(key, freq1);
      policyStats.recordMiss();
      data.put(key, node);
      node.append();
      evict(node);
    }
docs: Adds the entry, creating an initial frequency list of 1 if necessary, and evicts if needed.