code: public char charAt(int pos)
    {
      int startChunk = pos >>> m_chunkBits;
  
      if (startChunk == 0 && m_innerFSB != null)
        return m_innerFSB.charAt(pos & m_chunkMask);
      else
        return m_array[startChunk][pos & m_chunkMask];
    }
docs: Get a single character from the string buffer.
  
  
  @param pos character position requested.
  @return A character from the requested position.