### Question:
SimpleMessage extends AbstractMessage implements TypedMessage { @Override public String getPayload() { return payload; } SimpleMessage(final String type, final String payload, final String messageId, final String receiptHandle);  SimpleMessage(final String type, final String payload); @Override String getType(); @Override String getPayload(); @Override String toString();  }### Answer:
@Test public void shouldReturnPayload() { final String type = randomString(); final String payload = randomString(); final String messageId = randomId(); final String receiptHandle = randomId(); final SimpleMessage message = new SimpleMessage(type, payload, messageId, receiptHandle); final String result = message.getPayload(); assertEquals(payload, result); }