### Question:
CloseSessionOptionBuilder { public CloseSessionOption build() { validate(); return new CloseSessionOption(cameraRef, releaseCameraRef, camera); }  CloseSessionOptionBuilder setCameraRef(final EdsCameraRef cameraRef); CloseSessionOptionBuilder setReleaseCameraRef(final boolean releaseCameraRef); CloseSessionOptionBuilder setCamera(final CanonCamera camera); CloseSessionOption build();  }### Answer:
@Test void build() { final CloseSessionOption option = builder .setCameraRef(cameraRef) .build(); final String l = option.toString(); }
@Test void buildThrowsIfCameraRefNull() { Assertions.assertThrows(IllegalStateException.class, () -> builder.build()); }