@Override
  public boolean containsLongKey(long currentKey) {
    // Method only supported by FAST HashTable implementations
    throw new UnsupportedOperationException();
  }
Root interface for a vector map join hash table (which could be a hash map, hash multi-set, or
hash set).
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/mapjoin/optimized/VectorMapJoinOptimizedHashTable.java