public Builder withFiles(Map<Path, String> files) {
            Map<Path, MockApplicationFile> mockFiles = new HashMap<>();
            for (var file : files.entrySet())
                mockFiles.put(file.getKey(), new MockApplicationFile(file.getKey(),
                                                                     root, file.getValue()));
            this.files = mockFiles;
            return this;
        }
Additional (mock) files that will exist in this application package, with their content.
config-model/src/main/java/com/yahoo/config/model/test/MockApplicationPackage.java