code: void putAll(BaseRow sortKey, Collection<BaseRow> values) {
  		treeMap.put(sortKey, values);
  		currentTopNum += values.size();
  	}
docs: Puts a record list into the buffer under the sortKey.
  Note: if buffer already contains sortKey, putAll will overwrite the previous value
  
  @param sortKey sort key with which the specified values are to be associated
  @param values record lists to be associated with the specified key