### Question:
CloseSessionOptionBuilder { public CloseSessionOptionBuilder setCameraRef(final EdsCameraRef cameraRef) { this.cameraRef = Objects.requireNonNull(cameraRef); return this; }  CloseSessionOptionBuilder setCameraRef(final EdsCameraRef cameraRef); CloseSessionOptionBuilder setReleaseCameraRef(final boolean releaseCameraRef); CloseSessionOptionBuilder setCamera(final CanonCamera camera); CloseSessionOption build();  }### Answer:
@Test void setCameraRef() { final CloseSessionOption option = builder .setCameraRef(cameraRef) .build(); Assertions.assertNotNull(option.getCameraRef()); Assertions.assertFalse(option.getCamera().isPresent()); Assertions.assertTrue(option.isReleaseCameraRef()); }
@Test void setCameraRefThrowsOnNull() { Assertions.assertThrows(NullPointerException.class, () -> builder.setCameraRef(null)); }