return new SampleElements<>("one", "two", "three", "four", "five");
    }

    @Override
    public SampleElements<String> sampleValues() {
      return new SampleElements<>("january", "february", "march", "april", "may");
    }

    @Override
    public Collection<String> createCollection(Iterable<? extends String> values) {
      return Lists.newArrayList(values);
    }

    @Override

necessary.  Here is a sample; alter the names:

  Yoyodyne, Inc., hereby disclaims all copyright interest in the
  library `Frob' (a library for tweaking knobs) written by James Random
  Hacker.

  {signature of Ty Coon}, 1 April 1990
  Ty Coon, President of Vice

    Yoyodyne, Inc., hereby disclaims all copyright interest in the
    program `Gnomovision' (which makes passes at compilers) written by
    James Hacker.

    signature of Ty Coon, 1 April 1989
    Ty Coon, President of Vice

This General Public License does not permit incorporating your program
into proprietary programs. If your program is a subroutine library, you