### Question:
ChangeParamValidator extends ProposalValidator implements ConsensusCritical { private void validationChange(double currentParamValue, double inputValue, Param param) throws ParamValidationException { validationChange(currentParamValue, inputValue, param.getMaxDecrease(), param.getMaxIncrease(), param); } @Inject  ChangeParamValidator(DaoStateService daoStateService, PeriodService periodService, BsqFormatter bsqFormatter); @Override void validateDataFields(Proposal proposal); void validateParamValue(Param param, String inputValue);  }### Answer:
@Test public void testGetChangeValidationResult() throws ParamValidationException { ChangeParamValidator changeParamValidator = new ChangeParamValidator(null, null, new BsqFormatter()); try { changeParamValidator.validationChange(0, 0, 2, 2, Param.UNDEFINED); Assert.fail(); } catch (ParamValidationException e) { Assert.assertEquals(e.getError(), ParamValidationException.ERROR.SAME); } try { changeParamValidator.validationChange(0, 1, 2, 2, Param.UNDEFINED); Assert.fail(); } catch (ParamValidationException e) { Assert.assertEquals(e.getError(), ParamValidationException.ERROR.NO_CHANGE_POSSIBLE); } try { changeParamValidator.validationChange(0, -1, 2, 2, Param.UNDEFINED); Assert.fail(); } catch (ParamValidationException e) { Assert.assertEquals(e.getError(), ParamValidationException.ERROR.NO_CHANGE_POSSIBLE); } try { changeParamValidator.validationChange(2, 4, 2, 1.1, Param.UNDEFINED); Assert.fail(); } catch (ParamValidationException e) { Assert.assertEquals(e.getError(), ParamValidationException.ERROR.TOO_HIGH); } try { changeParamValidator.validationChange(4, 2, 1.5, 2, Param.UNDEFINED); Assert.fail(); } catch (ParamValidationException e) { Assert.assertEquals(e.getError(), ParamValidationException.ERROR.TOO_LOW); } changeParamValidator.validationChange(4, 2, 2, 2, Param.UNDEFINED); changeParamValidator.validationChange(2, 4, 2, 2, Param.UNDEFINED); changeParamValidator.validationChange(0, 1, 0, 0, Param.UNDEFINED); changeParamValidator.validationChange(0, -1, 0, 0, Param.UNDEFINED); changeParamValidator.validationChange(-1, 0, 0, 0, Param.UNDEFINED); changeParamValidator.validationChange(1, 0, 0, 0, Param.UNDEFINED); }