### Question:
OpenIDConnectClientBuilder { public OpenIDConnectClientBuilder setClientSecret(String clientSecret) { if (clientSecret == null || clientSecret.trim().isEmpty()) throw new IllegalArgumentException("ClientSecret must not be null or empty"); this.clientSecret = clientSecret.trim(); return this; }  static OpenIDConnectClientBuilder create(); OpenIDConnectClient build(); OpenIDConnectClientBuilder setAuthorizeUrl(String authorizeUrl); OpenIDConnectClientBuilder setTokenUrl(String tokenUrl); OpenIDConnectClientBuilder setClientId(String clientId); OpenIDConnectClientBuilder setClientSecret(String clientSecret); void setLoginFormAdapter(LoginFormAdapter loginFormAdapter);  }### Answer:
@Test public void testNullClientSecret() { thrown.expect(IllegalArgumentException.class); builder.setClientSecret(null); }
@Test public void testNotValidClientSecret() { thrown.expect(IllegalArgumentException.class); builder.setClientSecret(" "); }
@Test public void testValidClientSecret() { builder.setClientSecret("somesecret"); }