### Question:
MongoDbUser extends UserImpl { @Override public int hashCode() { int hash = 7; hash = 67 * hash + (this.getId() != null ? this.getId().hashCode() : 0); return hash; } MongoDbUser(String id);  MongoDbUser(); List<String> getAuthorityCodes(); PageLayoutRepository getPageLayoutRepository(); void setAuthorityCodes(List<String> authorityCodes); List<MongoDbPersonAssociation> getFriends(); void setFriends(List<MongoDbPersonAssociation> friends); @Override void setAuthorities(Collection<Authority> authorities); @Override Collection<GrantedAuthority> getAuthorities(); @Override void addAuthority(Authority authority); @Override void removeAuthority(Authority authority); @Override PageLayout getDefaultPageLayout(); @Override boolean equals(Object o); @Override int hashCode(); void setPageLayoutRepository(PageLayoutRepository pageLayoutRepository);  }### Answer:
@Test public void hashCode_Valid(){ user.setId("123"); assertNotNull(user.hashCode()); }
@Test public void hashCode_Null(){ assertNotNull(user.hashCode()); }