SetImpl extends BaseFinishedSqlPart implements Set { @Nullable @Override public SqlPart previous() { return mPrevious; } SetImpl(@NotNull final String[] columnNames, @NotNull final SqlPart previous); @NotNull @Override UpdateValues values(@NotNull final Object... values); @Override void prependTo(@NotNull final RawSqlBuilder builder); @Nullable @Override SqlPart previous(); int getColumnCount();  }
@Test public void previous_returnsProperItem() { SqlPart sqlPart = mock(SqlPart.class); SetImpl set = new SetImpl(new String[] {"a"}, sqlPart); SqlPart result = set.previous(); assertThat(result, is(sqlPart)); }