@Before
  public void setUp() throws Exception {
    RoleHierarchyImpl roleHierarchy = new RoleHierarchyImpl();
    roleHierarchy.setHierarchy("ROLE_A > ROLE_B");
    final UserDetails user =
        new User(
            "EXISTING_USER",
            "PASSWORD",
            true,
            true,
            true,
            true,
            AuthorityUtils.createAuthorityList("ROLE_A"));
    final UserDetailsService wrappedUserDetailsService = mock(UserDetailsService.class);
    when(wrappedUserDetailsService.loadUserByUsername("EXISTING_USER")).thenReturn(user);
    when(wrappedUserDetailsService.loadUserByUsername("USERNAME_NOT_FOUND_EXCEPTION"))
        .thenThrow(new UsernameNotFoundException("USERNAME_NOT_FOUND_EXCEPTION"));

    this.wrappedUserDetailsService = wrappedUserDetailsService;
    userDetailsServiceWrapper = new UserDetailsServiceWrapper();
    userDetailsServiceWrapper.setRoleHierarchy(roleHierarchy);
    userDetailsServiceWrapper.setUserDetailsService(wrappedUserDetailsService);
  }