@Override
 public String getTokenValue() {
   return reverse.getTokenValue();
 }
 @Override
 public MergeDirection getDirection() {
   return reverse.getDirection().reverseDirection();
 }
 @Override
 public String getTokenName() {
   return "Can not execute the reverse of " + reverse.getTokenName();
 }
  public void testForeignKey() throws Exception {
    dropTableIfPresent("NEW_TABLE");
    dropTableIfPresent("NEW_TABLE2");

    assertTokensAndExecute(0, 0);

    DbEntity dbEntity1 = new DbEntity("NEW_TABLE");

    DbAttribute e1col1 = new DbAttribute("ID", Types.INTEGER, dbEntity1);
    e1col1.setMandatory(true);
    e1col1.setPrimaryKey(true);
    dbEntity1.addAttribute(e1col1);

    DbAttribute e1col2 = new DbAttribute("NAME", Types.VARCHAR, dbEntity1);
    e1col2.setMaxLength(10);
    e1col2.setMandatory(false);
    dbEntity1.addAttribute(e1col2);

    map.addDbEntity(dbEntity1);

    DbEntity dbEntity2 = new DbEntity("NEW_TABLE2");
    DbAttribute e2col1 = new DbAttribute("ID", Types.INTEGER, dbEntity2);
    e2col1.setMandatory(true);
    e2col1.setPrimaryKey(true);
    dbEntity2.addAttribute(e2col1);
    DbAttribute e2col2 = new DbAttribute("FK", Types.INTEGER, dbEntity2);
    dbEntity2.addAttribute(e2col2);
    DbAttribute e2col3 = new DbAttribute("NAME", Types.VARCHAR, dbEntity2);
    e2col3.setMaxLength(10);
    dbEntity2.addAttribute(e2col3);

    map.addDbEntity(dbEntity2);

    // create db relationships
    DbRelationship rel1To2 = new DbRelationship("rel1To2");
    rel1To2.setSourceEntity(dbEntity1);
    rel1To2.setTargetEntity(dbEntity2);
    rel1To2.setToMany(true);
    rel1To2.addJoin(new DbJoin(rel1To2, e1col1.getName(), e2col2.getName()));
    dbEntity1.addRelationship(rel1To2);
    DbRelationship rel2To1 = new DbRelationship("rel2To1");
    rel2To1.setSourceEntity(dbEntity2);
    rel2To1.setTargetEntity(dbEntity1);
    rel2To1.setToMany(false);
    rel2To1.addJoin(new DbJoin(rel2To1, e2col2.getName(), e1col1.getName()));
    dbEntity2.addRelationship(rel2To1);
    assertSame(rel1To2, rel2To1.getReverseRelationship());
    assertSame(rel2To1, rel1To2.getReverseRelationship());

    assertTokensAndExecute(4, 0);
    assertTokensAndExecute(0, 0);

    // create ObjEntities
    ObjEntity objEntity1 = new ObjEntity("NewTable");
    objEntity1.setDbEntity(dbEntity1);
    ObjAttribute oatr1 = new ObjAttribute("name");
    oatr1.setDbAttributePath(e1col2.getName());
    oatr1.setType("java.lang.String");
    objEntity1.addAttribute(oatr1);
    map.addObjEntity(objEntity1);
    ObjEntity objEntity2 = new ObjEntity("NewTable2");
    objEntity2.setDbEntity(dbEntity2);
    ObjAttribute o2a1 = new ObjAttribute("name");
    o2a1.setDbAttributePath(e2col3.getName());
    o2a1.setType("java.lang.String");
    objEntity2.addAttribute(o2a1);
    map.addObjEntity(objEntity2);

    // create ObjRelationships
    assertEquals(0, objEntity1.getRelationships().size());
    assertEquals(0, objEntity2.getRelationships().size());
    ObjRelationship objRel1To2 = new ObjRelationship("objRel1To2");
    objRel1To2.addDbRelationship(rel1To2);
    objRel1To2.setSourceEntity(objEntity1);
    objRel1To2.setTargetEntity(objEntity2);
    objEntity1.addRelationship(objRel1To2);
    ObjRelationship objRel2To1 = new ObjRelationship("objRel2To1");
    objRel2To1.addDbRelationship(rel2To1);
    objRel2To1.setSourceEntity(objEntity2);
    objRel2To1.setTargetEntity(objEntity1);
    objEntity2.addRelationship(objRel2To1);
    assertEquals(1, objEntity1.getRelationships().size());
    assertEquals(1, objEntity2.getRelationships().size());
    assertSame(objRel1To2, objRel2To1.getReverseRelationship());
    assertSame(objRel2To1, objRel1To2.getReverseRelationship());

    // remove relationship and fk from model, merge to db and read to model
    dbEntity2.removeRelationship(rel2To1.getName());
    dbEntity1.removeRelationship(rel1To2.getName());
    dbEntity2.removeAttribute(e2col2.getName());
    List<MergerToken> tokens = createMergeTokens();
    assertTokens(tokens, 2, 1);
    for (MergerToken token : tokens) {
      if (token.getDirection().isToDb()) {
        execute(token);
      }
    }
    assertTokensAndExecute(0, 0);
    dbEntity2.addRelationship(rel2To1);
    dbEntity1.addRelationship(rel1To2);
    dbEntity2.addAttribute(e2col2);

    // try do use the merger to remove the relationship in the model
    tokens = createMergeTokens();
    assertTokens(tokens, 2, 0);
    // TODO: reversing the following two tokens should also reverse the order
    MergerToken token0 = tokens.get(0).createReverse(mergerFactory());
    MergerToken token1 = tokens.get(1).createReverse(mergerFactory());
    if (!(token0 instanceof DropRelationshipToModel && token1 instanceof DropColumnToModel
        || token1 instanceof DropRelationshipToModel && token0 instanceof DropColumnToModel)) {
      fail();
    }
    execute(token0);
    execute(token1);

    // check after merging
    assertNull(dbEntity2.getAttribute(e2col2.getName()));
    assertEquals(0, dbEntity1.getRelationships().size());
    assertEquals(0, dbEntity2.getRelationships().size());
    assertEquals(0, objEntity1.getRelationships().size());
    assertEquals(0, objEntity2.getRelationships().size());

    // clear up
    dbEntity1.removeRelationship(rel1To2.getName());
    dbEntity2.removeRelationship(rel2To1.getName());
    map.removeObjEntity(objEntity1.getName(), true);
    map.removeDbEntity(dbEntity1.getName(), true);
    map.removeObjEntity(objEntity2.getName(), true);
    map.removeDbEntity(dbEntity2.getName(), true);
    resolver.refreshMappingCache();
    assertNull(map.getObjEntity(objEntity1.getName()));
    assertNull(map.getDbEntity(dbEntity1.getName()));
    assertNull(map.getObjEntity(objEntity2.getName()));
    assertNull(map.getDbEntity(dbEntity2.getName()));
    assertFalse(map.getDbEntities().contains(dbEntity1));
    assertFalse(map.getDbEntities().contains(dbEntity2));

    assertTokensAndExecute(2, 0);
    assertTokensAndExecute(0, 0);
  }