code: public LongStreamEx append(long... values) {
          if (values.length == 0)
              return this;
          return new LongStreamEx(LongStream.concat(stream(), LongStream.of(values)), context);
      }
docs: Returns a new {@code LongStreamEx} which is a concatenation of this
  stream and the stream containing supplied values
  
  <p>
  This is a <a href="package-summary.html#StreamOps">quasi-intermediate
  operation</a>.
  
  @param values the values to append to the stream
  @return the new stream