### Question:
GroupByImpl extends BaseFinishedSelectStatement implements GroupBy { @NotNull @Override public Limit limit(final long limit) { return new LimitImpl(limit, this); } GroupByImpl(@NotNull final String expression, @NotNull final SqlPart previous); @NotNull @Override OrderBy orderBy(@NotNull final String... terms); @NotNull @Override Limit limit(final long limit); @Override void prependTo(@NotNull final RawSqlBuilder builder); @Nullable @Override SqlPart previous();  }### Answer:
@Test public void limit_returnsNotNullValue() { GroupByImpl groupBy = new GroupByImpl("a", mock(SqlPart.class)); Limit result = groupBy.limit(5); assertThat(result, is(notNullValue())); }