guava/src/com/google/common/cache/LocalCache.java
ReferenceEntry<K, V> getEntry(@Nullable Object key) {
    // does not impact recency ordering
    if (key == null) {
      return null;
    }
    int hash = hash(key);
    return segmentFor(hash).getEntry(key, hash);
  }
ReferenceEntry<K, V> getEntry(@Nullable Object key) {
    // does not impact recency ordering
    if (key == null) {
      return null;
    }
    int hash = hash(key);
    return segmentFor(hash).getEntry(key, hash);
  }
Returns the internal entry for the specified key. The entry may be loading, expired, or
partially collected.