* elements but rowKeySet() will be empty and containsRow() won't
     * acknowledge them.
     */
    rowKeyToIndex = Maps.indexMap(rowList);
    columnKeyToIndex = Maps.indexMap(columnList);

    @SuppressWarnings("unchecked")
    @Nullable V[][] tmpArray = (@Nullable V[][]) new Object[rowList.size()][columnList.size()];
    array = tmpArray;

    PowerSet(Set<E> input) {
      checkArgument(
          input.size() <= 30, "Too many elements to create power set: %s > 30", input.size());
      this.inputSet = Maps.indexMap(input);
    }

    @Override
    public int size() {
      return 1 << inputSet.size();
    }

    @Override
    public boolean isEmpty() {
      return false;
    }

	}
}

func TestMigrateWithQuotedIndex(t *testing.T) {
	if DB.Dialector.Name() != "mysql" {
		t.Skip()
	}

	type QuotedIndexStruct struct {
		gorm.Model
		Name string `gorm:"size:255;index:AS"` // AS is one of MySQL reserved words
	}

	if err := DB.Migrator().DropTable(&QuotedIndexStruct{}); err != nil {
		t.Fatalf("Failed to drop table, got error %v", err)
	}