### Question:
TokenProvider implements InitializingBean { public boolean validateToken(String authToken) { try { Jwts.parser().setSigningKey(key).parseClaimsJws(authToken); return true; } catch (JwtException | IllegalArgumentException e) { log.info("Invalid JWT token."); log.trace("Invalid JWT token trace.", e); } return false; } TokenProvider(JHipsterProperties jHipsterProperties); @Override void afterPropertiesSet(); String createToken(Authentication authentication, boolean rememberMe); Authentication getAuthentication(String token); boolean validateToken(String authToken);  }### Answer:
@Test public void testReturnFalseWhenJWThasInvalidSignature() { boolean isTokenValid = tokenProvider.validateToken(createTokenWithDifferentSignature()); assertThat(isTokenValid).isEqualTo(false); }
@Test public void testReturnFalseWhenJWTisUnsupported() { String unsupportedToken = createUnsupportedToken(); boolean isTokenValid = tokenProvider.validateToken(unsupportedToken); assertThat(isTokenValid).isEqualTo(false); }
@Test public void testReturnFalseWhenJWTisInvalid() { boolean isTokenValid = tokenProvider.validateToken(""); assertThat(isTokenValid).isEqualTo(false); }