parquet-hadoop/src/main/java/org/apache/parquet/hadoop/LruCache.java
public V remove(final K key) {
    V oldValue = cacheMap.remove(key);
    if (oldValue != null) {
      LOG.debug("Removed cache entry for '{}'", key);
    }
    return oldValue;
  }
public V remove(final K key) {
    V oldValue = cacheMap.remove(key);
    if (oldValue != null) {
      LOG.debug("Removed cache entry for '{}'", key);
    }
    return oldValue;
  }
Removes the mapping for the specified key from this cache if present.
@param key key whose mapping is to be removed from the cache
@return the previous value associated with key, or null if there was no
mapping for key.