code: private String readToEnd(InputStream inputStream) {
          Scanner scanner = new Scanner(inputStream).useDelimiter("\\A");
  
          return scanner.hasNext() ? scanner.next() : "";
      }
docs: Reads the stream until it has no more bytes and returns a UTF-8 encoded
  string representation.
  
  @param inputStream Stream to read from.
  @return UTF-8 encoded string representation of stream's contents.