code: public static final <T> Stream<T> appendStream(final Stream<T> stream1, final Stream<T> append) {
          return Stream.concat(stream1, append);
      }
docs: Append Stream to this Stream
  
  <pre>
  {@code
  List<String> result = 	of(1,2,3).appendStream(of(100,200,300))
  .map(it ->it+"!!")
  .collect(CyclopsCollectors.toList());
  
  assertThat(result,equalTo(Arrays.asList("1!!","2!!","3!!","100!!","200!!","300!!")));
  }
  </pre>
  
  @param stream1 to append to
  @param append to append with
  @return Stream with Stream appended