@Test
public void innerJoinStudentInstructorClassDeptHeadOnAge() {

  Table table1 = createSTUDENT();
  Table table2 = createINSTRUCTOR();
  Table table3 = createCLASS();
  Table table4 = createDEPTHEAD();
  Table joined = table1.joinOn("Age").inner(true, table2, table3, table4);
  assert (joined
      .columnNames()
      .containsAll(
          Arrays.asList(
              "T2.ID",
              "T2.City",
              "T2.State",
              "T2.USID",
              "T2.GradYear",
              "T3.ID",
              "T4.ID",
              "T4.First",
              "T4.Last",
              "T4.City",
              "T4.State")));
  assertEquals(30, joined.columnCount());
  assertEquals(14, joined.rowCount());
}