public synchronized ImmutableList<Struct> readTableRecords(String tableId, String... columnNames)
      throws IllegalStateException {
    return readTableRecords(tableId, ImmutableList.copyOf(columnNames));
  }
@Test
  public void testReadRecordsShouldThrowExceptionWhenCalledBeforeExecuteDdlStatement() {
    ImmutableList<String> columnNames = ImmutableList.of("SingerId");

    assertThrows(
        IllegalStateException.class, () -> testManager.readTableRecords("Singers", columnNames));
    assertThrows(
        IllegalStateException.class, () -> testManager.readTableRecords("Singers", "SingerId"));
  }