EndImpl extends BaseSqlPart implements End { @Nullable @Override public SqlPart previous() { return null; }  @NotNull @Override FinishedStatement transaction(); @Override void prependTo(@NotNull final RawSqlBuilder builder); @Nullable @Override SqlPart previous();  }
@Test public void previous_returnsNull() { EndImpl end = new EndImpl(); SqlPart result = end.previous(); assertThat(result, is(nullValue())); }