### Question:
OpenIDConnectClientBuilder { public OpenIDConnectClientBuilder setClientId(String clientId) { if (clientId == null || clientId.trim().isEmpty()) throw new IllegalArgumentException("ClientID must not be null or empty"); this.clientId = clientId.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 testNullClientId() { thrown.expect(IllegalArgumentException.class); builder.setClientId(null); }
@Test public void testNotValidClientId() { thrown.expect(IllegalArgumentException.class); builder.setClientId(" "); }
@Test public void testValidClientId() { builder.setClientId("someid"); }