@Test
public void setInvalidFormatId() {

    HouseId hid;
    hid = new HouseId("123456");
    assertFalse("Id's length 6 must be invalid", hid.isValidFormat());
    hid = new HouseId("1234567890");
    assertFalse("Id's length 10 must be invalid", hid.isValidFormat());
    hid = new HouseId("");
    assertFalse("Id's length 0 must be invalid", hid.isValidFormat());
    hid = new HouseId("123456789012");
    assertFalse("Id's length 12 must be invalid", hid.isValidFormat());
    hid = new HouseId("123456789012345");
    assertFalse("Id's length 15 must be invalid", hid.isValidFormat());
    hid = new HouseId("ab34/6789x1");
    assertFalse("Not only digit must be invalid", hid.isValidFormat());
    hid = new HouseId("1234x678901");
    assertFalse("Not only digit must be invalid", hid.isValidFormat());
    hid = new HouseId("-----------");
    assertFalse("only slash sign must be invalid", hid.isValidFormat());
}