code: public static boolean isCompressed(String input) throws IOException {
          return input != null && Base64.isBase64(input) &&
                  isCompressed(Base64.decode(input.getBytes(StandardCharsets.UTF_8)));
      }
docs: Determines if a String is compressed. The input String <b>must be Base64 encoded</b>.
  The java.util.zip GZip implementation does not expose the GZip header so it is difficult to determine
  if a string is compressed.
  
  @param input String
  @return true if the String is compressed or false otherwise
  @throws java.io.IOException if the byte array of String couldn't be read