code: public StringBuffer append(InputStream source, StringBuffer buffer) throws IOException
  	{
  		Reader _reader = FileTools.createReaderForInputStream(source, getEncoding());
  		return append(_reader, buffer);
  	}
docs: Load a text from the specified file and put it in the provided StringBuffer.
  
  @param source source stream.
  @param buffer buffer to load text into.
  @return the buffer
  @throws IOException if there is a problem to deal with.