code: void setSource(Reader reader) {
  		if (reader == null) {
  			throw new IllegalArgumentException("'reader' must not be null.");
  		}
  
  		br =
  				(reader instanceof BufferedReader) ? (BufferedReader) reader : new BufferedReader(
  						reader);
  	}
docs: Sets an Reader as the {@code JSON} feed.
  @param reader
  A Reader. Cannot be null.