code: @MustBeLocked (ELockType.WRITE)
    public void deleteDocuments (final Term... aTerms) throws IOException
    {
      final long nSeqNum = _getWriter ().deleteDocuments (aTerms);
      if (LOGGER.isDebugEnabled ())
        LOGGER.debug ("Last seq# after deleteDocuments is " + nSeqNum);
      m_aWriterChanges.incrementAndGet ();
    }
docs: Deletes the document(s) containing any of the terms. All given deletes are
  applied and flushed atomically at the same time.
  
  @param aTerms
  array of terms to identify the documents to be deleted
  @throws CorruptIndexException
  if the index is corrupt
  @throws IOException
  if there is a low-level IO error