### Question:
ScrollBarAdapter implements GriffonPivotAdapter, org.apache.pivot.wtk.ScrollBarListener { public void unitIncrementChanged(org.apache.pivot.wtk.ScrollBar arg0, int arg1) { if (unitIncrementChanged != null) { unitIncrementChanged.call(arg0, arg1); } }  CallableWithArgs<Void> getOrientationChanged(); CallableWithArgs<Void> getScopeChanged(); CallableWithArgs<Void> getUnitIncrementChanged(); CallableWithArgs<Void> getBlockIncrementChanged(); void setOrientationChanged(CallableWithArgs<Void> orientationChanged); void setScopeChanged(CallableWithArgs<Void> scopeChanged); void setUnitIncrementChanged(CallableWithArgs<Void> unitIncrementChanged); void setBlockIncrementChanged(CallableWithArgs<Void> blockIncrementChanged); void orientationChanged(org.apache.pivot.wtk.ScrollBar arg0, org.apache.pivot.wtk.Orientation arg1); void scopeChanged(org.apache.pivot.wtk.ScrollBar arg0, int arg1, int arg2, int arg3); void unitIncrementChanged(org.apache.pivot.wtk.ScrollBar arg0, int arg1); void blockIncrementChanged(org.apache.pivot.wtk.ScrollBar arg0, int arg1);  }### Answer:
@Test public void testUnitIncrementChanged() { final boolean[] invoked = new boolean[1]; CallableWithArgs<Void> callable = new CallableWithArgs<Void>() { public Void call(Object... args) { invoked[0] = true; return null; } }; assertNull(adapter.getUnitIncrementChanged()); adapter.unitIncrementChanged(null, 0); assertFalse(invoked[0]); adapter.setUnitIncrementChanged(callable); adapter.unitIncrementChanged(null, 0); assertTrue(invoked[0]); }