### Question:
SpringModelAdjuster implements ModelAdjuster { public void setModelKey(final String modelKey) { this.modelKey = modelKey; }  @Override @Nullable Object adjust(@Nullable final Object obj); void setModelKey(final String modelKey); String getModelKey();  }### Answer:
@Test public void setModelKey() throws Exception { springModelAdjuster.setModelKey("newModelKey"); Assert.assertEquals("model key should be 'newModelKey'", "newModelKey", springModelAdjuster.getModelKey()); }