filter.init(filterConfig);
MockHttpServletRequest originalRequest = new MockHttpServletRequest();
originalRequest.setMethod("POST");
originalRequest.setContentType("multipart/form-data");
originalRequest.addHeader("Content-type", "multipart/form-data");
HttpServletResponse response = new MockHttpServletResponse();
filter.doFilter(originalRequest, response, filterChain);
CommonsMultipartFile file1 = (CommonsMultipartFile) files.get(0);
CommonsMultipartFile file2 = (CommonsMultipartFile) files.get(1);
assertTrue(((MockFileItem) file1.getFileItem()).deleted);