@Test
public void innerJoinMultipleColumnsAllColumnsInJoinKey() {

  Table table1 =
      Table.create(SP500.dateColumn("Date"), SP500.dateColumn("Date").copy().setName("Date2"));
  Table table2 =
      Table.create(
          ONE_YEAR.dateColumn("Date"), ONE_YEAR.dateColumn("Date").copy().setName("Date2"));
  Table joined = table1.joinOn("Date", "Date2").inner(table2);
  assertEquals(5, joined.rowCount());
  assertEquals(2, joined.columnCount());
}