@Test
  public void testCreateGroupMembership() {
    Account account = new Account();
    account.setGivenName("Anthony");
    account.setSurname("Wolski");
    account.setEmail("*****@*****.**");
    account.setPassword("password");
    account.setUsername("awolski");
    accountService.createAccount(account);

    Group group = new Group();
    group.setName("Test Group");
    accountService.createGroup(group);

    GroupMembership groupMembership = new GroupMembership(account, group);
    accountService.createGroupMembership(groupMembership);

    List<Account> groupAccounts = accountService.getGroupAccounts(group.getId());
    assertEquals(1, groupAccounts.size());

    List<Group> accountGroups = accountService.getAccountGroups(account.getId());
    assertEquals(1, accountGroups.size());

    List<GroupMembership> groupGroupMemberships =
        accountService.getGroupGroupMemberships(group.getId());
    assertEquals(1, groupGroupMemberships.size());

    List<GroupMembership> accountGroupMemberships =
        accountService.getAccountGroupMemberships(account.getId());
    assertEquals(1, accountGroupMemberships.size());
  }