The anatomy of a good testcase

tests.java

@Test
public void shouldWorkAccordingToInstructions() {
  //given (instructor is a mock injected in a worker)
  given(instructor.getInstructions()).willReturn(particularInstructions);
  
  //when (operate the SUT)
  ParticularResult result = workerUnderTest.work();
  
  //then
  then(instructor).should.getInstructions();
  assertThat(result, is(createdAccordingTo(particularInstructions));
}