code: protected int _writeString(String string) throws IOException {
  		//reserve space for the string size
  		int p = _buffer.size();
  		_buffer.putInt(0);
  
  		//write string
  		int l = _writeCString(string);
  
  		//write string size
  		_buffer.putInt(p, l);
  		return l + 4;
  	}
docs: Write a BSON string structure (a null terminated string prependend by the length of the string)
  
  @param string The string to write
  @return The number of bytes written, including the terminating null byte and the size of the string
  @throws IOException If an error occurred in the stream while writing