fixture
    // create the test situation out of given commands and/or events
    .givenCommands(...) // optional
    .andGiven(...) // optional
    .andGivenCommands() // optional

    .when(command) // define which command you want to test

    // multiple optional expectation matchers
    .expectSuccessfulHandlerExecution() // optional
    .expectEvents(...) // optional
    .expectState(...) // optional