code: public StringBuffer append(Reader source, StringBuffer buffer) throws IOException
  	{
  		BufferedReader _bufferedReader = new BufferedReader(source);
  		char[] _buffer = new char[getBufferSize()]; // load by chunk of 4 ko
  		try
  		{
  			for (int _countReadChars = 0; _countReadChars >= 0;)
  			{
  				buffer.append(_buffer, 0, _countReadChars);
  				_countReadChars = _bufferedReader.read(_buffer);
  			}
  		}
  		finally
  		{
  			_bufferedReader.close();
  		}
  		return buffer;
  	}
docs: Load a text from the specified reader and put it in the provided StringBuffer.
  
  @param source source reader.
  @param buffer buffer to load text into.
  @return the buffer
  @throws IOException if there is a problem to deal with.