### Question:
OidcSecurityDetailsServiceImpl implements OidcSecurityDetailsService { @Override public String getTokenUser() { Authentication authentication = getAuthentication(); if (authentication == null) return null; return authentication.getName(); }  @Override String getTokenRealm(); @Override String getTokenUser();  }### Answer:
@Test void getTokenUser() { assertThat(securityDetailsService.getTokenUser(), is(LOGIN)); SecurityContextHolder.getContext().setAuthentication(null); assertNull(securityDetailsService.getTokenUser()); }