code: public static Observable<byte[]> encode(Observable<String> src, String charsetName) {
          return encode(src, Charset.forName(charsetName));
      }
docs: Encodes a possibly infinite stream of strings into an Observable of byte arrays.
  <p>
  <img width="640" src="https://raw.github.com/wiki/ReactiveX/RxJava/images/rx-operators/St.encode.png" alt="">
  
  @param src
  @param charsetName
  @return the Observable with a stream of encoded byte arrays