### Question:
MandrillSimpleEmailSender implements SimpleEmailSender { @Override public void send(final SimpleEmailMessage message) { Assert.notNull(message,"Null was passed as an argument for parameter 'message'."); mandrillApiCommunicator.sendEmail(message); } MandrillSimpleEmailSender(final MandrillApiCommunicator mandrillApiCommunicator); @Override void send(final SimpleEmailMessage message);  }### Answer:
@Test public void testSendWithInvalidArguments(){ assertThatThrownBy(()-> mandrillSimpleEmailSender.send(null)) .isInstanceOf(IllegalArgumentException.class); }
@Test public void testSend(){ final SimpleEmailMessage message = SimpleEmailMessage.of(uuid(), uuid(), uuid(), uuid(), Collections.emptySet()); mandrillSimpleEmailSender.send(message); verify(mandrillApiCommunicator).sendEmail(message); }