FullHalfPairsBuilder { public FullHalfPairsBuilder pair(String fullwidth, String halfwidth) { this.pairs.add(new FullHalfPair(fullwidth, halfwidth)); return this; }  FullHalfPairsBuilder pair(String fullwidth, String halfwidth); FullHalfPairsBuilder appendablePredicate(
            FullHalfPairs.AppendablePredicate predicate); FullHalfPairs build();  }
@Test public void testSamePairIsIgnored() { Set<FullHalfPair> set = new FullHalfPairsBuilder().pair("ａ", "a").pair( "ａ", "a").build().pairs(); assertThat(set.size(), is(1)); }