### Question:
CustomExceptionHandler { @ExceptionHandler(ConversionFailedException.class) public ResponseEntity<QueryResponse> handleConversionFailedException(ConversionFailedException e) { ApiError apiError = new ApiError(400, "Invalid request param : " + e.getMessage()); QueryResponse queryResponse = new QueryResponse(); queryResponse.setErrors(List.of(apiError)); return new ResponseEntity<>(queryResponse, HttpStatus.BAD_REQUEST); }  @ExceptionHandler(OpaClientException.class) ResponseEntity<QueryResponse> handleOpaClientException(OpaClientException e); @ExceptionHandler(PartialEvauationException.class) ResponseEntity<QueryResponse> handlePartialEvaluationException(PartialEvauationException e); @ExceptionHandler(ConversionFailedException.class) ResponseEntity<QueryResponse> handleConversionFailedException(ConversionFailedException e); @ExceptionHandler(IllegalArgumentException.class) ResponseEntity<QueryResponse> handleIllegalArgumentExceptionException(IllegalArgumentException e); @ExceptionHandler(Exception.class) ResponseEntity<QueryResponse> handleException(Exception e);  }### Answer:
@Test void shouldHandleConversionFailedException() { ResponseEntity<QueryResponse> result = target.handleConversionFailedException(new ConversionFailedException(null, null, null, new IllegalArgumentException("conversionFailedException"))); assertThat(result, is(notNullValue())); assertThat(result.getStatusCodeValue(), is(400)); }